The family of murdered journalist Daphne Caruana Galizia say they are "dismayed" at how Prime Minister Joseph Muscat is putting himself at the centre of the investigation into her assassination.  

In a statement they called on Dr Muscat to distance himself from the probe because of Yorgen Fenech's links to his chief of staff Keith Schembri and Tourism Minister Konrad Mizzi.

Mr Fenech was arrested this week in connection with the October 2017 murder and is being questioned by the police.

Malta's police commissioner has not given any update on the investigation with the public instead relying on Dr Muscat for details.

"As investigators now turn to Fenech’s corrupt links with the Maltese Prime Minister’s chief of staff Keith Schembri and cabinet minister Konrad Mizzi, we are dismayed to see the Prime Minister putting himself at the centre of the investigation," the family said.

"We remind Prime Minister Joseph Muscat that the assassination investigation implicates his own office and his closest officials.

"The Prime Minister has no place anywhere near the investigation and we trust that he will now distance himself from it."

They threatened legal action to "ensure that the investigation is independent and impartial, and that it runs its full course".

"Too many people have worked too hard for too long for justice. The Prime Minister should not derail, in one final attempt, full justice for our wife and mother."

Last year Times of Malta revealed Mr Fenech as the owner of a mystery Dubai company called 17 Black. 

It was one of two sources of income for the Panama companies Hearnville and Tillgate, which were set up by consultants for Mr Schembri and Dr Mizzi.   

Earlier on Friday, the Prime Minister's involvement in the investigation was also questioned by the Council of Europe rapporteur Pieter Omtzigt. 

“Given his associations, shouldn’t PM Muscat be keeping his distance from all of this?" he said.