On a two-day visit that began Thursday, five members of the European Parliament committee in charge of the probe are looking into the case of Khaled el-Masri, a German of Lebanese origin. He has accused the CIA of kidnapping him in late 2003 from Macedonia and interrogating him in Afghanistan.

Skopje has denied any involvement in the alleged operation by the US spy agency.

Upon arrival, the delegation met Macedonian President Branko Crvenkovski and were due to meet Deputy Prime Minister Radmila Secerinska and former foreign minister Slobodan Casule, the EU spokesman Andrea Angeli told AFP news agency.

"The target is the truth, just the truth," the EU lawmaker leading the probe, Claudio Fava, told reporters after the meeting with Crvenkovski.

The EU deputies are scheduled to meet former interior minister Siljan Avramovski, his successor Ljubomir Mihajlovski and parliamentary speaker Ljupco Jordanovski on Friday.

Earlier this year European deputies decided to set up a special committee to look into the allegations that the Central Intelligence Agency secretly operated flights carrying prisoners it considered terror suspects which passed through EU territory.

The parliament's inquiry started in January and is expected to issue a first report next month.

More than 1,000 secret CIA flights have gone through European airspace and airports since 2001 without governments requesting information, Fava said upon presenting a preliminary report.

"It is hard to believe that the authorities and governments of certain countries were unaware of what was going on on their territory. Our probe shows that they must have known," Fava said.

Fava singled out Sweden, Italy and Bosnia for particular criticism. For more than three months, the EU parliamentary inquiry has heard testimony from alleged victims and human rights groups -- all saying that European states had handed over terrorism suspects to foreign agents, and ignoring hundreds of CIA flights that had used their airports. Some former detainees provided detailed accounts of alleged torture carried out in secret prisons outside EU or US jurisdiction.

The EU lawmakers investigating the Khalid al-Masri case in Macedonia want to find out how the plane with al-Masri on board could leave Europe unchallenged.

Fava believes that there were hundreds of similar incidents. "If we look at all the testimonies we have got, it becomes very clear that these incidents weren't sporadic, but that it was a common practice. That's the only conclusion I can draw," Fava said.

The CIA declined to comment on the EU parliamentarians' findings. The inquiry committee has no legal powers, but it will recommend what political action should be taken against any countries found to have been involved, including the United States. Several EU lawmakers are expected to go to Washington in early May to try to meet Secretary of State Condoleezza Rice and CIA chief Porter Goss.

The European Union has granted Macedonia candidate status, but no date has been set to begin talks for membership in the bloc.