Bulgarian nurse Kristiana Valcheva, center, is carried by an unidentified man upon arrival in the Bulgarian capital, Sofia. Five Bulgarian nurses and a Palestinian doctor were pardoned by President Georgi Parvanov on Tuesday, after spending eight years in prison in Libya.

Sofia, Bulgaria ? Five Bulgarian medical workers arrived home to an emotional welcome Tuesday after more than eight years in Libyan prisons, closing a case that caused international furor over Libyan justice and raised questions about whether a ransom was paid for their release.

The five nurses and a doctor – a Palestinian who was granted Bulgarian citizenship last month – flew to freedom aboard a French government jet. On stepping down from the plane in Sofia, Bulgaria’s capital, they received a pardon from their president, bouquets and the embraces of teary-eyed family members.

“I know I am free, I know I am on Bulgarian soil, but I still cannot believe it,” declared nurse Kristiana Valcheva, 48.

Arrested in 1999, she and the others were sentenced to death on charges of intentionally infecting more than 400 Libyan children with HIV, the virus that causes AIDS. Libyan authorities accused them of conducting an AIDS experiment that went wrong.

The nurses and the doctor blamed the infections on poor hygiene in the hospital where they worked. Independent medical studies showed that the infections there predated their arrival by several years.

Their release followed complex behind-the-scenes negotiations that resulted in the payment of hundreds of millions of dollars, much of it from foreign sources, to the families of the infected children and promises of improved trade and aid ties between Libya and the European Union.

European and U.S. officials depicted the release as the latest step by Libyan leader Moammar Gadhafi to normalize relations between his nation, once a pariah, and its former adversaries in the West.

“It’s the end of a nightmare for these women and this man. Everyone in Europe is convinced that they are innocent,” said French President Nicolas Sarkozy, whose wife, Cecilia, went to Libya on Sunday with Benita Ferrero-Waldner, the EU external relations commissioner, to press for the release.

Both women accompanied the medical workers on their flight from Libya on the French presidential plane.