The courts in Athens have refused an appeal by a Greek prosecutor on the decision not to extradite Pilatus Bank whistleblower Maria Efimova to Malta.

The Russian national had fled Malta last year after a European and international arrest warrant was issued by the Maltese courts when she failed to turn up to court hearings.

Ms Efimova was behind allegations that the Panama company Egrant was owned by the Prime Minister’s wife, Michelle Muscat, a claim that was first reported by slain journalist Daphne Caruana Galizia and which is strongly denied by the Muscats.

In a decision handed down on Thursday morning, the Greek courts of appeal confirmed that Ms Efimova would not be extradited to Malta.

The whistleblower turned herself in to the Greek police in March, prompting a group of MEPs - who had formed the European Parliament delegation on the rule of law – to write to the Greek authorities calling on them to protect Efimova and ensure she was not returned to Malta.

In April, the courts in Athens had ruled that the whistleblower would not be extradited to Malta because of concerns for her safety, a decision that was then appealed by prosecutors.

Reacting to the news, PN MEP David Casa, who has been in close contact with Ms Efimova throughout the ordeal, said he welcomed the decision of the Greek courts.

"I am hopeful that this will give Maria the peace of mind and tranquillity she very much deserves," the MEP said.