The migrant from South Sudan, Lam Magok, alleges he was imprisoned in a Tripoli detention centre run by Osama Almasri Najim -- who is wanted by the International Criminal Court (ICC) on charges including murder, rape and torture.

Najim was detained in the northern Italian city of Turin on January 19 on an ICC warrant, only to be released and flown home to Tripoli on an Italian air force plane two days later.

Magok claims he was beaten and kicked by the police chief and his guards, according to the reports, which said Prime Minister Giorgia Meloni and two senior ministers were named in his complaint.

The complaint filed in Rome could prompt an investigation from prosecutors.

"The Italian government has made me a victim twice, nullifying the possibility of obtaining justice both for all the people, like me, who survived his violence," he wrote, according to passages of the lawsuit published by local media.

Neither Magok's lawyer nor Meloni's government immediately replied to a request for comment or confirmation.

Najim's repatriation has caused a major political row in Italy, and a special court is considering an investigation into Meloni and her justice and interior ministers for their role into Najim's release.

Meloni has called the probe politically motivated.

In a press conference at parliament last week, Magok said he and other migrants were beaten when they tried to flee Tripoli's Mitiga detention centre run by Najim.

The police chied "beat us, tortured us for days," said Magok, according to Italian news agency Ansa, adding that he was forced to remove dead migrants' bodies.

"It was something that I will never forget and it is unthinkable that one might be forced to do this. We want justice," he said.

Justice Minister Carlo Nordio and Interior Minister Matteo Piantedosi are also named in Magok's complaint, according to reports.

Najim was freed after an Italian appeals court ruled he could not be detained in jail due to a technicality involving Nordio failing to respond in time to the ICC request.

Piantedosi then claimed the government had no choice but to repatriate Najim because he was considered too dangerous to remain in Italy.

Meloni has also defended the expulsion of the Libyan police chief, asking why the ICC only issued the warrant as he entered Italy after "spending a dozen calm days in three other European countries."