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.
Daphne 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, had links to high-level politicians.
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.
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 had benefited from secretive “shell companies”. Mr Schembri and the minister both denied any wrongdoing.