Former chief justice Vincent De Gaetano has revealed that he initially agreed to chair the public inquiry into Daphne Caruana Galizia's assassination but withdrew after what he described as "constant attempts at interference" in how the inquiry would operate.

Speaking to Andrew Azzopardi on Campus FM on Saturday, De Gaetano said he eventually felt he would be drawn into "constant skirmishes" and was being used.

His comments come less than two weeks after former prime minister Joseph Muscat publicly revealed that De Gaetano had been considered for the inquiry as he recounted the discussions that led to the final composition of the board.

De Gaetano said he was still serving as Malta's judge at the European Court of Human Rights in Strasbourg when then justice minister Owen Bonnici contacted him on behalf of Cabinet and asked whether he would chair the inquiry.

After considering the request, De Gaetano said he agreed in principle, but wanted to see the terms of reference and receive assurances that they would be acceptable to both the Parliamentary Assembly of the Council of Europe and the Caruana Galizia family.

He said a series of exchanges followed and broad agreement was reached. He had proposed a five-member board instead of three, but the government did not accept the proposal.

The main issue for De Gaetano, he said, was a provision stating that the inquiry board would regulate its own procedure.

However, he said that despite this provision, he began receiving a series of emails containing suggestions about how the inquiry should operate, including how questions should be asked and who should ask them.

De Gaetano said he was not due to return to Malta before November and had expected to meet the other members of the board to agree on their procedures. Instead, he said, suggestions about the inquiry's internal workings continued.

He stressed that Bonnici remained "nothing but cordial" and that the proposals were presented as suggestions rather than instructions.

One suggestion, he recalled, was that, as had happened with the Egrant inquiry, there could be one report for public release and another for the prime minister.

De Gaetano said he repeatedly reminded Bonnici that the terms of reference placed responsibility for procedural decisions with the inquiry board.

"Either you trust that the board is going to regulate its own procedures, or you don't," he said.

Eventually, De Gaetano said, he became frustrated by what he considered persistent attempts to interfere with the inquiry's workings and told Bonnici he was no longer interested in chairing it.

The inquiry was eventually made up of retired judge Michael Mallia, former chief justice Joseph Said Pullicino and Judge Abigail Lofaro.

Muscat recently said he had initially proposed forensic expert Anthony Abela Medici and law professor Ian Refalo, as well as De Gaetano. The government's first proposed board in September 2019 included Mallia, Refalo and Abela Medici, but Refalo and Abela Medici subsequently withdrew following discussions with the Caruana Galizia family.

The final terms of reference were also broadened, requiring the board to examine whether wrongful action or inaction by the state had facilitated the assassination or failed to prevent it.

The inquiry concluded in 2021 that the state should shoulder responsibility for Caruana Galizia's assassination, finding that a culture of impunity had developed at the highest levels of government and that the state had failed to recognise and act on the risks to her life.

It did not find evidence that the government had been directly involved in carrying out the assassination.

De Gaetano said the inquiry's conclusions remained valid despite the subsequent acquittal of Yorgen Fenech, who was found not guilty on September 2 of complicity in Caruana Galizia's murder and conspiracy to have her killed.

He instead questioned what had happened since the inquiry ended.

"The inquiry happened and the conclusions are what they are. How many of its recommendations have been implemented?" he asked.

A Daphne Caruana Galizia Foundation assessment published earlier this year found that only two of the inquiry's 26 recommendations had been fully implemented, while another two had been partially implemented.