Melvin Theuma completed a week of testimony in the Yorgen Fenech murder trial on Friday, with the defence spending much of the final day challenging his credibility, his account of his meetings at Castille and his claim that he acted on Fenech's instructions to arrange the assassination of Daphne Caruana Galizia.

Theuma, the self-confessed middleman, was questioned at length by defence lawyer Gianella De Marco before prosecutor Godwin Cini carried out a brief re-examination. The jury also put a series of direct questions to him before his testimony came to an end.

The proceedings were at times tense, with Judge Edwina Grima intervening repeatedly as the questioning became heated. At one point, the judge reprimanded de Marco after she told Theuma that he should be ashamed of himself. Cini also drew a reprimand after shouting an objection.

A central theme of Saturday's questioning - which came after two days of on-site visits to places linked with the murder - was Theuma's account of his visits to Auberge de Castille and his meetings with former chief of staff Keith Schembri.

Theuma maintained that he had only met Schembri twice before the murder - once at a dinner at Yorgen Fenech's ranch and once at Castille - and insisted that he had visited the Prime Minister's office only once before the assassination.

The defence, however, produced an Office of the Prime Minister visitor slip dated March 2, 2017, which carried Theuma's identity card number and indicated a visit to Neville Craus lasting from 12.51pm until 3.30pm.

Theuma vehemently denied the document, saying it was false and insisting that he had never signed paperwork when visiting Castille. He asked the court to appoint an expert to compare the signature on the visitor slip with his actual signature.

De Marco also confronted Theuma with text messages sent around the time he obtained his controversial phantom government job. In one message, dated February 28, 2017, he told his partner's daughter that he had been given a government job and had "power". He later referred to a meeting at Castille scheduled for March 1.

The defence highlighted what it described as a chronological contradiction, given that Theuma had already obtained the government job by then. Theuma nevertheless insisted that he had no other meetings at Castille.

The defence also repeatedly questioned Theuma about the alleged murder plot and whether someone with the profile of Caruana Galizia could have been killed without powerful backing.

De Marco argued that Caruana Galizia was a high-profile journalist and that Theuma, who had driven her in his taxi, knew who she was. She suggested that the scale of the murder meant that the killers would have wanted to know who was behind the operation.

Theuma rejected the suggestion, insisting that Alfred Degiorgio, whom he approached to carry out the killing, was interested only in whether he would be paid. He said no names were given to the hitmen at that stage.

Theuma also recounted his version of how the assassination was commissioned. He said Fenech had called him to meet near the Hilton and instructed him to contact George Degiorgio to have Caruana Galizia killed. Theuma said he subsequently contacted Darren Debono, known as it-Topo, and Alfred Degiorgio, known as il-Fulu, to arrange a meeting.

When De Marco asked whether he would simply kill someone because Fenech told him to, Theuma admitted to having been blindly compliant with Fenech, saying he would do anything for him.

The court also had to rule on the scope of Theuma's presidential pardon after de Marco questioned him about whether he had supplied drugs to Fenech. Judge Grima ruled that the pardon was not a blanket pardon and applied specifically to five listed offences. The court warned that Theuma could be prosecuted for offences not covered by the pardon if he incriminated himself.

Theuma subsequently refused to answer questions about whether he had supplied drugs to Fenech, repeatedly invoking his right not to reply.

His emotional state was also evident during Friday's sitting. At one point, while discussing his relationship with Fenech, Theuma told the judge he could not take any more. He said he did not know why Fenech had chosen him to carry out the murder.

Later, he spoke of his remorse over the killing, saying that he regretted becoming involved in a murder and taking a woman's life. He said his remorse was immense and would remain with him for the rest of his life.

Before leaving the witness stand, Theuma answered questions directly from the jurors, including about the phantom job, his meetings at Castille and the financial arrangements surrounding the assassination. He then thanked the judge, jurors, bailiffs, lawyers and his wife before ending six days of testimony.

The trial resumes on Monday.

A minute-by-minute account of today's hearing can be found here