Joseph Muscat has filed an application before the first hall of the civil court in its constitutional jurisdiction calling for Magistrate Gabriella Vella not to continue to lead the inquiry into the privatisation of three state hospitals.
He is also calling for the inquiry to be transferred to another magistrate "who would be objectively and subjectively impartial".
In a Facebook post, the former prime minister said the filing shows clearly that Magistrate Vella could not continue leading the inquiry because of continuous leaks, including from her investigators and because for more than a year, she did not accept his numerous requests to testify.
The magistrate, he wrote, accepted a report against him without granting him the legal right to reply, and she did not recuse herself despite public comments on the merits of the case by her close relatives.
"There is also numerous case law that indicates that the magistrate should have recused herself," he added.
Magistrate Vella turned down Muscat's request to recuse herself earlier this month, and the former prime minister immediately replied that he would be taking "all the necessary steps" to ensure that the process treated him with fairness.
"I will take all the necessary steps to ensure that the process, in which I have lost almost all trust, does not end up a political theatre as some intend it to be, but rather a process according to the rule of law," he had said in a statement uploaded on Facebook.
Magistrate Vella is leading a probe that is looking into possible corruption in the privatisation process. Muscat's home was searched in January 2022 in connection with the probe.
Earlier this month, Times of Malta reported that investigators suspect consultancy payments that the former prime minister received in the months after he resigned were intended to hide kickbacks in plain sight.
Of particular interest is €60,000 that Muscat received from companies linked to the failed privatisation deal. The payments were part of a 36-month, €15,000-a-month consultancy contract Muscat signed, though payments stopped abruptly after four months.
Muscat reacted to the investigation by saying he was being framed, that information was being leaked from the inquiry and demanding that magistrate Vella step down immediately.
He said family members of hers had "promoted propaganda" by those who filed the inquiry [Rule of law NGO Repubblika] and said the magisterial probe should be continued by someone else "who can secure impartiality".