Britain and the new Libyan government were at loggerheads last night over whether the Lockerbie bomber and Yvonne Fletcher's suspected killer could be removed from the country.
Pressure has been growing for Abdelbaset Ali Mohmed al-Megrahi to be brought back to jail in the UK in the wake of the collapse of Muammar Gaddafi's regime.
Scotland Yard has also identified former Libyan diplomat Abdulmagid Salah Ameri as the prime suspect in the 1984 shooting of WPC Fletcher in London.
Foreign Secretary William Hague struck an optimistic note on the cases yesterday, saying National Transitional Council (NTC) chairman Mustafa Abdel Jalil had pledged to "cooperate fully".
"I would say that when chairman Jalil... was with us in London in May he committed himself and the council to cooperating fully with the British government on this issue," Mr Hague said.
"It is true, it is a fact, that there is no extradition treaty with Libya. But we look to them to cooperate fully."
Mr Hague played down comments by junior NTC members that extraditions would be blocked, insisting they were not the "last word".
However, new justice minister Mohammed al-Alagi became the most senior figure so far to rule out handing individuals over.
"We will not give any Libyan citizen to the West," he told reporters in Tripoli.
"Al-Megrahi has already been judged once and he will not be judged again. We do not hand over Libyan citizens. (Muammar) Gaddafi does."
Al-Megrahi was convicted and imprisoned in Scotland for the bombing of Pan Am flight 103, which killed 270 people.
He was granted compassionate release in 2009 on the basis that he was expected to die from prostate cancer within months. But he is still alive and was residing in Tripoli until the Gaddafi regime fell.
No-one has ever been prosecuted over the murder of WPC Fletcher, who was shot while policing a protest outside the Libyan embassy.