Defence lawyers say the children already had the virus which causes Aids

They were found guilty of deliberately infecting about 400 children in Libya with HIV/Aids - a verdict international critics said was unsound.

Nineteen Bulgarian medical workers are arrested at a hospital in the Libyan city of Benghazi after an outbreak of HIV/Aids among children being treated there. Thirteen are later freed.

Five Bulgarian women nurses and a Bulgarian male doctor go on trial along with a Palestinian doctor and eight Libyans on charges of deliberately infecting hundreds of children with HIV-contaminated blood products. The indictment says 23 of the infected children have died.

As Bulgaria calls on Libya to ensure the accused receive a fair trial, and the medical workers complain of being tortured into signing confessions they could not read in Arabic, proceedings are repeatedly postponed.

After at least 13 adjournments, Libya says a verdict is imminent. Other charges against the Bulgarians include drinking in public and engaging in extramarital sex. The Bulgarians and Palestinian all plead not guilty. The Libyan defendants are freed on bail. Amnesty International reports "serious irregularities in... pre-trial proceedings" and Bulgaria accuses Libya of holding a political trial.

After further adjournments, the case is passed from the Libyan People's Court in Tripoli, which deals with matters of state security, to an ordinary criminal court. The defendants' Libyan lawyer argues that the HIV infections were probably due to poor hygiene and the reuse of syringes in the hospital.

The French doctor who first isolated the HIV virus, Luc Montagnier, testifies that the hospital Aids epidemic was probably caused by poor hygiene, and that it began before the accused started working at the hospital.

Libya convicts and sentences the five Bulgarian nurses and Palestinian doctor to death by firing squad for infecting the children. The Bulgarian doctor is given a four-year sentence for currency smuggling.

Libyan Foreign Minister Abdelraham Shalgam says the guilty verdicts could be re-examined if victims are compensated.

Nine Libyan policemen and a Libyan doctor go on trial accused of torturing the five Bulgarian nurses in custody. They are acquitted in June.

Bulgarian President Georgi Parvanov visits Libya to meet both the infected children and the imprisoned nurses as Sofia steps up diplomatic pressure on Muammar Gaddafi's government.

The Bulgarian government rejects Libyan demands for "blood money" in order to secure the release of the five nurses, arguing that to pay any money would be to accept the women's guilt.

Bulgaria and Libya agree to set up a fund for the families of the infected Libyan children. Two days later, the Libyan Supreme Court overturns the convictions and orders a retrial of the Bulgarian nurses and Palestinian doctor.

Libyan families of infected children demand a total of 4.4bn euros ($5.5bn) in compensation from donors.

International scientists publish a study in Nature magazine finding that the Libyan children were infected by a strain of HIV which must have entered the hospital before the Bulgarians began working there.

A Libyan court again sentences the five Bulgarian nurses and a Palestinian doctor to death for knowingly infecting children with HIV. Their lawyer says they will appeal to the Supreme Court again.

Muammar Gaddafi rejects calls for the release of the six foreign medics sentenced to death. Those who committed crimes must accept the consequences, he says.

Othman Bizanti, the lawyer for the six foreign medics, appeals against the convictions to the Libyan Supreme Court. This is the last chance for the defence to have the guilty verdicts overturned.

A Libyan court dismisses separate defamation charges against the five Bulgarian nurses and a Palestinian doctor. The lawsuit was brought by a Libyan policeman and a Libyan doctor after being accused by the foreign medics of torture during investigations into their case.

German Foreign Minister Frank-Walter Steinmeier and EU External Relations Commissioner Benita Ferrero-Waldner hold talks in Libya to try to secure the medics' release. Saif al-Islam, who is Col Gaddafi's son, describes the initiative as "positive".

Libya's Supreme Court upholds the death penalty against the medics after an appeal - however there are hopes that a compensation deal reportedly agreed with the families could see the death penalties commuted to prison terms and lead to the medics' release.

Libya's top legal body, the High Judicial Council, overrules the Supreme Court decision and commutes the death penalty to life in prison, after relatives accept compensation reportedly worth $1m per child. The move could see all six transferred to Bulgaria to serve out their sentences.

The six are released from Libyan custody following a deal with the European Union to improve EU-Libya relations and a visit to Tripoli by Cecilia Sarkozy, the wife of France's new president. The six travel by plane to Bulgaria, accompanied by the European Union's external affairs commissioner, Benita Ferrero-Waldner, and Mrs Sarkozy.