"Very senior people" would be asked to answer the allegations of human rights violations on EU territory, said Sarah Ludford, vice president of an investigation into the alleged prisons being conducted by the parliament.
"I don't see why we should not invite Donald Rumsfeld and Dick Cheney," Ludford said. "I'm sure they would be very welcome and they would be heard with great interest, or (Secretary of State) Condoleezza Rice perhaps, why not?"
Ludford, a British Liberal Democrat party member, acknowledged that the parliament had no legal power to subpoena them.
"I would not be over optimistic, but I don't think it's completely off the planet to think that they might come to see us," she said.
The parliament committee held its first meeting Thursday, electing Portuguese Conservative Carlos Coelho as its president.
"I hope that we will be inviting very senior people from governments, from non-governmental organizations and people who have knowledge of the intelligence community," Ludford said. "If they are seen not to cooperate then I think we can draw conclusions."
The 732-member EU legislature agreed two weeks ago to launch its own investigation.
Allegations the CIA hid and interrogated key al Qaeda suspects at Soviet-era compounds in Eastern Europe were first reported Nov. 2 in The Washington Post.
Human Rights Watch has said it has circumstantial evidence indicating the CIA transported suspected terrorists captured in Afghanistan to Poland and Romania. Both countries have denied any involvement.
Secret prisons on European territory and extraordinary rendition
the practice of transporting criminals or terror suspects to countries where harsh interrogation methods are permitted — would breach human rights treaties which all EU countries signed up to.
The work of the 46-member committee is the first inquiry conducted by the EU. Several EU countries have launched their own investigations, as has the Council of Europe, the continent's top human rights watchdog.
The EU parliament committee was given a mandate to find out whether the CIA or other U.S. agencies or other countries carried out abductions, extraordinary rendition, detention at secret sites, and torture of prisoners in EU countries or have used EU countries to transfer prisoners.
"It's high time we start the investigation," said German Socialist Wolfgang Kriessl-Doerfler. "I assume that all governments have an interest to cooperate with us, to clear up the questions ... no secret service of the world may commit on European soil human right violations."
Coelho refused to be drawn on specific names he would favor, but said the committee as a whole would decide who to ask to attend the meetings, after which a report will be drafted and presented to EU governments. The committee's work is to last for four months, he said.
"We will be looking at these events which ostensibly were conducted by the CIA or other secret police forces on our territory," Coelho told the committee. "There may be citizens who may have been victims ... this is a very sensitive issue," He said he hoped the investigation would lead to further prove the existence of the secret prisons and find out if any of the 25 EU governments were involved.
A preliminary report by the Council of Europe, drafted by Swiss Sen. Dick Marty, accused European governments of turning a blind eye to breaches of human rights. His report however, failed to uncover tangible evidence proving clandestine detention centers existed in Romania or Poland as alleged by New York-based Human Rights Watch.
His interim report, based partly on results of national investigations and recent media reports, did not break new ground and largely repeated his previous claims that U.S. policies in the war on terror contravene international law on human rights.
Marty said that more than 100 suspects may have been transferred by U.S. agents to countries where they faced torture or ill treatment in recent years.