The case of five Bulgarian nurses and a Palestinian trainee doctor convicted by a Libyan court of knowingly infecting 438 children with HIV dragged on for nearly a decade.
All six were sentenced to death after being convicted but in July 2007 their sentences were commuted to life in prison after the families of the children agreed to accept compensation believed to be worth $1m (£500,000) per child.
They were finally released and sent to Bulgaria after a deal struck in Tripoli improving Libyan-European Union ties.
The medics say they were tortured into making false confessions
Q: How long were they in custody?
The six medics were arrested in Benghazi in February 1999 along with 13 others, who were later released. Their trial began a year later and they were convicted in 2004. They were in custody throughout this time.
Q: What was final trigger for their release?
The newly elected French President, Nicolas Sarkozy, and his wife, Cecilia, became closely involved in the case and the medics returned to Sofia on a French government plane, but it was mainly the result of years of patient behind-the-scenes efforts by the European Commission.
While Bulgaria was preparing to become a member of the EU, the European External Affairs Commissioner, Benita Ferrero Waldner, made numerous trips to Libya, meeting the prisoners and working to improve conditions for the hundreds of children infected with HIV-Aids.
Q: What is in the deal that won their freedom?
EU officials say the key to the agreement was a memorandum signed in Tripoli by Mrs Ferrero Waldner which would in effect lead to the full normalisation of relations between the EU and Libya.
The memorandum includes a promise to open the European market to Libyan farm and fishery produce, technical assistance for the restoration of archaeological monuments and EU grants for Libyan students.
Q: Who paid the compensation?
The money was paid out of a fund set up by the Gaddafi Foundation, a charity run by a son of Libyan leader Muammar Gaddafi. Libya says that both France and the European Union contributed but this was denied by French President Nicolas Sarkozy who insisted that neither his country nor the EU had paid "the slightest financial compensation". They are believed to share Bulgaria's view that any payment would amount to a recognition of the medics' guilt.
Q: How reliable are the convictions?
The six retracted early confessions, saying they had been made under torture (police officers accused of torturing them were acquitted in a separate trial). The case against them has been taken apart by international experts including Luc Montagnier, the French co-discoverer of HIV. They testified that the HIV infections pre-dated the defendants' arrival in Benghazi in 1998 and that the probable real cause was poor standards of hospital hygiene. However, the testimony was disregarded by the court.
Q: What do we know of the infected children?
Little is known outside Libya about the condition of the children. Since the outbreak began, at least 56 of them have died. Some of those infected are reported to have passed the virus on to
Q: How sensitive has the case been for Libya?
Some of the surviving infected children and their families repeatedly called for the verdicts - death by firing squad - to be carried out. The Benghazi region, with its strong tribal traditions and potential for Islamic radicalism, has represented something of a problem for Libyan leader Muammar Gaddafi. At the same time, Mr Gaddafi has been working on his country's international rehabilitation, which has advanced in recent years following his compliance with the Lockerbie judgement and Libya's announcement that it was abandoning its pursuit of weapons of mass destruction. But Libya's leader did not want to be seen to be acting under foreign pressure.
How has the case affected Libya's image abroad?
Human Rights Watch has appealed for foreign pressure on Libya to reform its judicial system. The US-based advocacy group accuses Libya of using torture on suspects and rigging trials.
Q: How has Bulgaria handled the case?
The six convicted medics were all pardoned upon arrival in Sofia by Bulgarian President Georgi Parvanov who stressed his belief "in the innocence of the medical workers". Some of the families have accused the government of acting too late, and one family member has said he hopes to initiate court proceedings against two former foreign ministers and others for failing to secure the release.