Maltese Prime Minister Joseph Muscat says his chief of staff Keith Schembri has stood down as police extend their inquiry into the murder of journalist Daphne Caruana Galizia.
Mr Schembri was not available for comment but reports said he was assisting police.
The Caruana inquiry intensified last week with the arrest of Maltese businessman Yorgen Fenech.
A suspected middleman in the murder has been granted a presidential pardon.
Mr Muscat told parliament that the suspect, Melvin Theuma, was being given immunity in return for information about the killing. Maltese reports suggested he had audio recordings linked to the case.
The prime minister said on Tuesday that he would not speculate on whether his former chief of staff was being questioned or what that questioning could be about.
Caruana Galizia, an investigative journalist, was murdered in a car bombing in October 2017 after writing a series of blogs about corruption.
She alleged that a company called 17 Black, owned by Mr Fenech, and had links to high-level politicians. In her last blog, Caruana Galizia wrote about Keith Schembri.
Mr Fenech is also reported to have requested a pardon in exchange for information. He received hospital treatment after a dramatic arrest on his yacht.
Three people have so far been charged with carrying out the murder.
After Mr Fenech’s arrest last week, crowds outside parliament in Valletta demanded Mr Muscat’s resignation. There were further protests late on Monday and students called for renewed demonstrations on Tuesday.
According to Maltese reports, the prime minister said on Tuesday he had been given unanimous support in a meeting of his parliamentary group.
Mr Schembri was named in the massive data leak known as the Panama Papers and Caruana Galizia alleged he and a senior minister, Konrad Mizzi, had benefited from secretive “shell companies”.
Mr Schembri and the tourism minister have both denied any wrongdoing. Asked whether he would resign, Mr Mizzi said he would give a statement after a cabinet meeting on Tuesday.
Malta’s business community said the unfolding inquiry had revealed the extent of damage caused to the country.
In a statement, the chamber of commerce said it had become clear “the extent to which criminal activity had infiltrated the circles of power, and operated unperturbed for years”.