French prosecutors on Wednesday launched an investigation into the business dealings in France of a suspect in the 2017 killing of Maltese journalist Daphne Caruana Galizia.

In a statement they said were responding to a complaint filed in December by the family of the slain journalist and by French media rights campaigners Reporters Without Borders (RSF).

Financial investigators would try to establish if business dealings in France by people under investigation in Malta over the killing had been linked to corrupt practices abroad, the statement said.

The complaint named a number of senior figures being investigated by the Maltese police, including tycoon Jorgen Fenech.

Fenech, who owns hotels and a racing horse stable in France, has already been charged in Malta with complicity in Caruana Galizia's murder.

In their complaint, the family and RSF accused Fenech of having used money from his French assets to bribe two senior figures inside the Maltese administration to win a major public contract.

The complaint names them as Keith Schembri, former chief of staff to the then prime minister Joseph Muscat; and former tourism minister Konrad Mizzi.

Galizia Caruana was investigating this story when she was killed by a car bomb on October 16, 2017.

The assassination of Daphne Caruana Galizia eventually led to the resignation of several senior politicians in the wake of a string of revelations about the case and regular street protests
The assassination of Daphne Caruana Galizia eventually led to the resignation of several senior politicians in the wake of a string of revelations about the case and regular street protests AFP / STRINGER

Muscat resigned as prime minister in December following accusations that he had intervened to protect Schembri and Mizzi.

The French prosecutors, in their statement, made it clear they would be cooperating closely with the Maltese authorities.

Caruana Galizia's family and RSF welcomed the news.

"(It) sets an important standard in the prosecution of corruption across European borders and in the crimes committed against journalists," her sister Corinne Vella told AFP.

"Institutional failure and state capture in Malta has left our government without the will or capacity to deliver full justice."

RSF secretary general Christophe Deloire welcomed the new investigation as an important development.

Writing on Twitter, he said it might shed more light on the what had happened behind the scenes of the assassination.

The complaint he helped file in December also suggested that Fenech's French business assets might have been used to pay those hired to carry out the bombing.

Three men accused of the murder itself have already been arrested.

Shortly before her assassination, Caruana Galizia had revealed that a company based in Dubai, 17 Black, paid two million euros to Schembri and Mizzi.

After her death, a group of journalists who took up her investigation showed that 17 Black was owned by Fenech.

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