Bulgaria has asked Libya to give it custody of six foreign medics jailed for infecting hundreds of children with HIV.
Tripoli commuted death sentences on the six to life imprisonment on Tuesday, raising hopes they might be freed after eight years in jail.
"All necessary papers for the transfer have been sent to the Libyan authorities today. We are hoping for a swift answer," a Bulgarian Foreign Ministry spokesman said.
The six - five Bulgarian nurses and a Palestinian doctor - were convicted of deliberately infecting more than 400 Libyan children with the virus. The medics say they are innocent and that confessions were extracted under torture.
After diplomatic talks and payment of hundreds of millions of dollars to the families of 460 HIV victims, Tripoli commuted their sentences, opening the way for their transfer to Bulgaria under a prisoner exchange agreement.
Once in Sofia, the six could be pardoned by the Balkan country's president. Bulgaria granted citizenship to the Palestinian doctor last month.
EU newcomer Bulgaria and its allies in Washington and Brussels, who say the medics are innocent, have pushed for their release.
Foreign HIV experts testified during the case in Libya that the infections started before the six arrived at the hospital and were more likely to be due to poor hygiene.