There have been serious irregularities in ... pre-trial proceedings

Amnesty International

All the defendants pleaded not guilty.

The trial has provoked strong feelings in Bulgaria after two of the defendants alleged they had been tortured and made confessions under duress.

It has also raised concern among human rights groups who have complained about reports that HIV-contaminated plasma was discovered at a defendant's apartment while she was in police custody, and the refusal of the court to allow expert opinion from Switzerland and France.

Amnesty International has said "there have been serious irregularities in ... pre-trial proceedings".

Bad practices

Bulgaria has accused Libya of holding a political trial and has repeatedly called for an independent team of international experts to study the case and testify.

Luc Perrin, head of virology at Geneva University Hospital, said the contamination was caused by "bad medical practices."

Perrin, who examined 40 of the children, said at least half were also infected with hepatitis C, which suggests the hospital had reused needles.

The court has refused to allow Perrin to testify.

Libyan leader Muammar Gaddafi has said the CIA or Mossad, Israel's intelligence agency, were behind the childrens' illnesses.

He has blamed other crises on the United States and Israel, both of which accuse Libya of supporting terrorism.

Besides the murder and conspiracy counts, the Bulgarians are charged with drinking in public - alcohol is banned in Libya - and engaging in extramarital sex.

Nine Libyans charged in the same case are out on bail.

Othman el-Bezanti, the lawyer defending the Bulgarians, said that if they are found guilty, they have two stages of appeal.