Daphne Caruana Galizia's son Andrew told jurors about his mother's investigative work, her fears in the weeks before her assassination and the devastating impact her death had on the family, as his testimony brought the prosecution's case in Yorgen Fenech's jury trial to a close on Thursday.

Andrew Caruana Galizia, the prosecution's final witness, became visibly emotional as he recalled learning about the explosion in Bidnija on 16 October 2017 and realising that his mother was most likely the victim.

His testimony followed the conclusion of a lengthy cross-examination of Inspector Kurt Zahra, while the court also heard from IT expert Martin Bajada about internet access available on tablets used by the jurors.

Andrew told the court that he had returned to Malta in 2017 after eight years abroad and was living in Floriana with his wife. He regularly visited his mother and said that during the summer before her murder they had worked together on leaked material relating to the Electrogas project.

"This was a huge story. She was working 16 hours a day on this. She was looking for the people owning the company 17Black linked to Keith Schembri and Konrad Mizzi," he said.

"I saw the original emails leaked from Electrogas," he later added.

His testimony was repeatedly interrupted by defence objections over whether he was giving evidence which went beyond what he had previously testified to during the magisterial inquiry.

At one point, prosecutor Godwin Cini responded to the objections by saying: "With all due respect, his mother is the victim. Let him testify. The witness lost his mother."

A heated exchange followed, during which parte civile lawyer Jason Azzopardi objected to the defence's approach towards the witness. Judge Edwina Grima held Azzopardi in contempt and fined him €50.

The judge later rebuked the parties over their conduct, warning lawyers against making comments in front of jurors which could influence their eventual decision and saying further inappropriate behaviour could result in the lawyer responsible being ordered out of the courtroom.

Further legal arguments arose when Andrew testified about information obtained following his mother's death, including meetings with Electrogas shareholders.

He said Siemens representatives had described Electrogas as "a complete business failure," despite Fenech continuing to receive millions of euros.

Defence lawyer Charles Mercieca objected, arguing that the evidence was hearsay and involved opinions and technical matters.

Judge Grima ultimately ruled that Andrew could not testify about facts which had not been presented during the compilation of evidence, and only about what he testified to during the inquiry.

When the jury returned, Andrew was questioned about the weeks immediately preceding his mother's murder.

He recalled spending a day at his parents' Bidnija home around two weeks before the assassination, saying this was the first time he had become genuinely concerned for her.

"She said, 'they are trying to fry me alive'," Andrew recalled.

His mother was barely leaving the house and had started parking her car behind the gate, something he described as unusual because parking there was difficult.

"She was obviously worried about something," he said, adding that she was facing several legal threats as well as public and political harassment.

Andrew said violent threats had been directed at his mother since she was 25 and that the family had grown accustomed to them.

He became visibly emotional when recounting the day of the assassination.

His brother Matthew called to tell him that a car had exploded and urged him to go to Bidnija. Andrew tried calling his mother but received no answer.

"At that point, I knew it was most likely my mum," he said through tears.

Andrew said that following the murder, the family began seeing headlines suggesting that diesel smugglers and other criminals were responsible, which prompted them to decide on a legal strategy.

He described himself and his two brothers as extremely close and said the years of pressure they had experienced had strengthened their belief that they could confront what followed together.

"Because of the anger we suffered after my mother was killed, we found the energy to keep on working," he said, adding that all three brothers suffered health problems.

"Would I want to stop her? I wouldn't. I would warn her, but I would never tell her to stop what she was doing." He described his mother as someone who had sacrificed greatly for her family.

"She was good company. She was funny. She was an interesting woman. I miss her as a mother, but also as a friend, as an adviser, as a reference point in my life. It's hard to keep going without her."

The defence did not cross-examine him.

Earlier, court-appointed IT expert Martin Bajada presented the results of his examination of tablets used by the jurors after concerns were raised about their potential exposure to media coverage of the trial.

Bajada examined 489 pages of browsing activity and confirmed that the devices could connect to the internet and display news headlines and accompanying images, although jurors could not open the full articles.

He found only one entry concerning Fenech's request for a presidential pardon, which appeared after jurors had already heard about the pardon while watching Fenech's recorded police interrogation.

Bajada also said social media platforms could not be accessed through the tablets and found no evidence that a number of online publications specifically mentioned by the defence had been accessed.

He acknowledged, however, that the internet facility had been available since the beginning of the trial and said it had also surprised him that the devices had such access.

The defence also concluded its two-day cross-examination of Inspector Kurt Zahra.

Among the final issues raised, lawyer Giannella de Marco questioned him about whether police had independently verified aspects of Melvin Theuma's account.

Zahra said he had not personally questioned staff at the Blue Elephant after Theuma claimed Fenech commissioned the murder shortly after they left the restaurant, and did not know whether Keith Arnaud had done so.

Asked whether investigators checked flight information relating to the day Theuma claimed Fenech handed him money shortly before reaching the airport, Zahra said Arnaud had definitely carried out checks but he could not remember their outcome.

The defence also raised Vince Muscat's account of an alleged container of contraband cigarettes at the Freeport which Alfred Degiorgio had supposedly asked Theuma to help with shortly after the murder.

Zahra said the allegation had been investigated through Freeport officials but produced a negative result.

Before leaving the stand, Zahra was also asked about payment for the bomb used to assassinate Caruana Galizia.

He recalled George Degiorgio saying that he had spoken to Kevin Falzon, known as iċ-Ċoqqoq, who has since died, and paid him €20,000 for the explosive device.

"In organised crime, people are normally paid for the job," Zahra said.

On Thursday morning, the defence repeatedly challenged Inspector Kurt Zahra over the investigation into the assassination of Daphne Caruana Galizia, focusing particularly on statements allegedly implicating former government officials.

The morning session began with a legal dispute over Zahra's knowledge of matters discussed outside the courtroom, after he appeared to tell jurors that the defence had accused him of perjury.

Defence lawyer Charles Mercieca argued that this was particularly concerning because Zahra had previously undertaken not to follow media reports or discuss the proceedings while his testimony was ongoing. The defence said Zahra could only have learned about the accusation from information circulating outside the courtroom.

The judge ordered the jury to disregard Zahra's remark and warned the inspector that failure to comply with the court's instructions concerning media isolation could potentially lead to legal proceedings.

The issue became clearer when Zahra admitted that he had accessed Facebook, where he saw a post about a news article and read comments beneath it, although he insisted that he had not opened the article itself.

Judge Grima expressed strong disapproval, reminding him that he had been instructed to go home, speak to nobody and avoid all media coverage. Zahra apologised and said he had always told the truth.

The defence then returned to the substance of Zahra's evidence, concentrating on the statements made by convicted hitman Vince Muscat, known as il-Koħħu.

De Marco questioned Zahra about whether Muscat had ever told investigators that former OPM chief of staff Keith Schembri was behind the murder. Zahra said he did not recall Muscat making such a statement, while stressing that he had not been present during every interrogation.

De Marco also questioned Zahra about an alleged meeting at Chris Cardona's ministry. Zahra confirmed that he remembered Muscat saying that, after Theuma spoke to Alfred Degiorgio, the men went to the ministry. He said this occurred several days later and that, as far as he knew, they had gone there once to obtain information.

The defence then turned to Muscat's interrogation of 18 January 2020, when he was asked whether Caruana Galizia would have been killed if Melvin Theuma had never become involved.

According to the statement read in court, Muscat replied that he had "no doubt" that the assassination would still have happened. He referred to individuals by letters, saying "A sent him to C" and "I took him to D".

The defence said A referred to David Gatt, C to Schembri and D to Cardona. A diagram containing the coded letters had been shown to Muscat during questioning. Zahra confirmed that the purpose of using letters was to avoid mentioning the individuals' names during the recorded interrogation.

The exchanges over the diagram prompted Judge Grima to intervene, pointing out that the document was not part of the acts of the case. At one stage, when de Marco appeared to hold the diagram up in court, the judge ordered her to lower it.

Zahra repeatedly qualified his evidence by stressing that his memory was not perfect. When asked about whether Muscat had implicated Schembri and Cardona, he said he remembered the opposite in relation to one crucial point: Muscat had maintained that the assassination would not have happened if Theuma had not appeared with the €150,000.

The defence also questioned Zahra about warnings given to the suspected assassins before their arrest. Zahra confirmed that the suspects had known about their impending arrests around five days beforehand because Theuma had informed them.

He confirmed a chain of information which, according to his recollection, originated with Schembri, passed to Fenech, then to Theuma and finally reached the Degiorgio brothers.

Another major focus was audio evidence involving Theuma.

De Marco asked Zahra about recordings in which Theuma allegedly said that Schembri had repeatedly pressured him to kill Caruana Galizia. Zahra said he did not recall this, explaining that Inspector Keith Arnaud had been responsible for analysing the audio files.

The defence stressed that such an allegation would have been highly significant. Zahra again said he did not remember.

The defence further raised discrepancies concerning telephone calls between Schembri and Fenech around the time of Theuma's arrest. Zahra said Fenech had claimed Schembri called him around 30 times that day, but forensic analysis showed only four or five missed calls between November 14 and 15.

Zahra also explained that Schembri was arrested because investigators had established that he had passed a letter to Fenech through Dr Adrian Vella the previous day, while messages between Schembri and Fenech had been found on Fenech's phone on the eve of Fenech's attempted escape.

Towards the end of the morning, De Marco moved to the 2015 plot to assassinate Caruana Galizia which ultimately failed. Zahra confirmed details concerning the alleged €50,000 payment connected with that plot, while again warning that his recollection of events was not perfect.

Zahra was asked whether investigators had established whether Theuma had used a recording application on his phone to capture events as they happened, including any alleged commissioning of the murder by Fenech.

Zahra recalled that Theuma had told investigators he met Fenech at the Blue Elephant, but said he did not remember Theuma recording the telephone call allegedly preceding that meeting. When pressed on whether he had ever asked Theuma why he had a recording facility but apparently had not recorded such crucial events, Zahra replied: "I don't remember asking him."

The morning session was interrupted for nearly two hours because one of the jurors was feeling unwell. Meanwhile, the afternoon session was interrupted due to arguments between the lawyers.

With Andrew Caruana Galizia's evidence subsequently concluded, prosecutors confirmed that he was their final witness. The defence informed the court that they have between four and five witnesses expected to testify. The court adjourned proceedings until Friday at 9am.