A multi-millionaire businessman accused of organising the assassination of Maltese journalist Daphne Caruana Galizia claims he was covertly passed information on the investigation into the killing by the prime minister's right-hand man.
The allegations raise fresh questions about the extent to which senior government figures tried to interfere in the investigation into the car bombing in an attempt to cover up the crime.
Yorgen Fenech told a court in the capital Valletta on Thursday that he was kept updated on the police investigation by Keith Schembri, the government's chief of staff and a close friend of Joseph Muscat, the prime minister.
"Keith would inform me continuously, in real time," Mr Fenech said.
In what local media described as "shocking testimony", Mr Fenech said he was told by Mr Schembri that his telephone was being tapped and was tipped off about a raid conducted by police in December 2017, two months after the journalist was murdered by a car bomb.
He said Mr Schembri even gave him a script about what he should tell police when he was questioned about the murder. "I was to be very careful and not mention Schembri," he said.
He ignored those orders and instead implicated Mr Schembri in the car bombing.
"The recordings and the evidence all showed close ties between Schembri and the murder," he told the court.
Mr Fenech, who was arrested last month on his luxury yacht, was charged at the weekend with financing and organising the assassination, accusations he denies.
Mr Schembri resigned from his position last week and was subsequently arrested and questioned by police. He was later released without charge and denies any involvement in the murder.
The testimony from the business tycoon, one of Malta's richest men, will place even more pressure on the prime minister amid a deepening political crisis.
Asked by a reporter on Thursday whether he had any knowledge of the plot to kill the reporter, Mr Muscat replied: "Definitely not. I absolutely had no knowledge of the plot."
In an editorial, The Times of Malta said: "Muscat must now shoulder full responsibility for the reputational damage done to Malta, for the political crisis that has engulfed the country, the clear and present danger of civil strife it is facing and the economic damage that it may suffer."
Remarking on the court proceedings, David Casa, an MEP from the opposition Nationalist Party, wrote on Twitter: "Shocking - one of alleged murder masterminds states in court that PM's chief of staff was kept updated on case by lead investigator and notified all suspects of developments, including that their phones were tapped."
The prime minister announced this week that he will resign in January, but protesters, civil society groups and the Caruana Galizia family have demanded that he step down immediately.
Mr Muscat is due to meet Pope Francis at the Vatican on Saturday, but a group of Maltese academics has urged the pontiff to cancel the reception.
The group of 22 academics said they were "dismayed" that Mr Muscat would be going to the Vatican at a time when "following the revelation of criminal activity at the highest levels of power in our land, the calls for his resignation are flowing in from many quarters, not least EU institutions and the Council of Europe."
They called on the Pope not to take part in what they said would be a "propaganda exercise" for the prime minister.