Ashraf Alhajouj and five Bulgarian nurses were sentenced to death in Libya on charges of starting an HIV epidemic. After eight years in jail, the six were freed in July last year under a cooperation deal between Libya and the European Union.

The medics have always maintained their innocence and said they confessed under torture.

Alhajouj's Dutch lawyer Liesbeth Zegveld said the complaint was filed with the U.N. Human Rights Committee on Monday.

"It is over violation of the right not to be tortured, violation of the right to a fair trial ... eight-year delay of the procedure, illegal death penalty, illegal detention," she told Reuters by telephone from the Netherlands.

Last month, Alhajouj also filed a lawsuit in France against Libyan leader Muammar Gaddafi, accusing him of torture.

Zegveld said her client was seeking international recognition that he was innocent.

"He has been pardoned and sent to Bulgaria. But the verdict stays and someone needs to scratch out this verdict and a human rights committee has the right to do that at an international level," she added.

"The U.N. committee will decide whether Libya has violated the international human rights treaty ... It works like an international court but in a more loose manner in a sense that it's not a binding decision," the lawyer said.

Last year, Libya commuted the medics' death sentences to life imprisonment after the 460 HIV victims' families were paid $1 million each in a settlement financed by an international fund. Bulgarian President Georgi Parvanov pardoned the six after arriving in Sofia in July.

Zegveld has said Alhajouj delayed filing the complaint against Libya under political pressure from European politicians who tried to convince him not to press charges to avoid harming the EU's improving ties with Tripoli.

The return of medics to Bulgaria ended what critics called a human rights scandal and allowed the long-isolated north African country to complete a process of normalising ties with the West.

The six have said that before their release in July, they were made to sign an agreement that they would not start any legal procedures against Libya. Nine Libyan policemen and a doctor were acquitted of torturing the medics by a Libyan court.

International scientists say they have shown the HIV epidemic began in Libya before the foreign medics arrived.