Muscat, who has come under fire over his handling of the probe into the investigative blogger’s slaying two years ago, said Sunday he would step down after his replacement is chosen in January.
But the Labour leader’s decision to hang on for six weeks has angered those who say he should resign immediately over allegations he obstructed justice by protecting high-profile politicians implicated in the murder.
One of Caruana Galizia’s sons, Paul, said on Twitter that the family had called for police not only to stop Muscat having any further involvement in the investigation, but also “put him under investigation so as to disclose and preserve all evidence”.
Police sources said the answer to the request, which the family filed in court, was not expected imminently.
“Until he resigns, we will use all legal remedies to ensure Muscat has no further involvement in the investigation and criminal proceedings, other than as a possible suspect,” the family said in a statement.
Protesters demanding Muscat’s immediate departure were set to rally in parliament square later Monday, while a group backing the outgoing PM was organising a counter demonstration outside Labour party headquarters.
Caruana Galizia, a mother of three described as a “one-woman WikiLeaks”, was blown up in a car bomb near her home in October 2017.
The investigation into her murder has rocked the Mediterranean island, reaching the highest echelons of government.
A European Parliament delegation is due to arrive in the country late Monday and will meet members of the Caruana Galizia family, Muscat and the police commissioner, before heading back to Brussels on Wednesday.
Led by Dutch MEP Sophie in’t Veld, it will examine doubts about the judiciary’s independence and allegations of corruption.
The scandal has so-far claimed the scalps of Muscat’s top aide Keith Schembri and former tourism minister Konrad Mizzi, both of whom stepped down last week.
Caruana Galizia, who became known for exposing cronyism and sleaze within the country’s political and business elite, had alleged that Schembri and Mizzi had been involved in corruption, claims both men have denied.
Tycoon Yorgen Fenech, arrested as he tried to leave on his yacht, was charged Sunday with complicity in the murder.
Fenech has claimed Schembri was the “real mastermind” behind the killing, according to police sources.
Schembri was arrested last week, but released two days later, fuelling accusations of a cover-up.
Fenech had been attempting to get the chief investigator in the case, Keith Arnaud, removed — alleging that he had been informing Schembri of details in the murder probe.
But on Monday, he dropped his action on the same a court had been due to rule on the question.