The legal action was timed to coincide with a six-day visit to Paris by Gaddafi which has been dogged by controversy over human rights violations in the north African state.

Dr. Ashraf Alhajouj and the Bulgarian nurses were sentenced to death after being convicted of deliberately infecting 460 Libyan children with HIV, but were freed in July after long negotiations with European Union envoys and the intervention of French President Nicolas Sarkozy.

The lawsuit cited a 1984 international convention against torture, which was ratified by both France and Libya.

"Dr. Alhajouj is extremely grateful to France and the president for having extracted him from Gaddafi's prisons. But he believes that France, the country of human rights, should not have welcomed such a person here," said lawyer Francois Cantier.

The lawyer said the anti-torture convention could be invoked in France because of Gaddafi's presence in Paris. But his status as a head of state gives him diplomatic immunity and French prosecutors are highly unlikely to act on the lawsuit.

Cantier said the lawsuit also listed five members of the Libyan security forces, and a Libyan doctor who, his client said, had tortured him.

Gaddafi's son Saif al-Islam confirmed in August that the foreign medics had been tortured into confessing. "There was torture with electricity ... there was a threat to attack their families," he told Al Jazeera television.

Opposition leaders and even some government officials have accused Sarkozy of turning a blind eye to human rights violations in Libya in his haste to wrap up business deals with the energy-rich north African state.

Sarkozy has defended his decision to invite Gaddafi to Paris, saying he was an important figure in the Arab world and that Paris had to have an open dialogue with him.