In an embarrassing reversal, Britain admitted Thursday that one of its remote outposts — the Indian Ocean island of Diego Garcia — had twice been used by the United States as a refueling stop for the secret transfer of two terrorism suspects.

The CIA admitted that previous data given to America's strongest ally "turned out to be wrong." British Foreign Secretary David Miliband told Parliament that recent talks with Secretary of State Condoleezza Rice showed two suspects had been on flights to Guantanamo Bay and Morocco in 2002 that stopped on Diego Garcia, a U.S. base on British soil.

Former Prime Minister Tony Blair came under heavy criticism for Britain's close alliance with the United States in the war in Iraq and its part in the U.S.-led war on terrorism. The latest disclosure could pressure the United States to identify other countries used in extraordinary renditions, a practice of transferring suspects without formal extradition proceedings that human rights groups say opens the door for third-party countries to torture suspects.

Miliband told lawmakers he was "very sorry" to have to correct statements made by the government in 2005, 2006 and 2007 that there were no such transfers involving Britain.

He and Rice "both agree that the mistake made in these two cases are not acceptable, and she shares my deep regret that this information has only just come to light," said Miliband, who has sometimes broken ranks with the British government over military action in Iraq and policies in the Middle East.

The CIA acknowledged that the information previously provided to the British "turned out to be wrong," despite earlier U.S. assurances that none of the secret flights since the Sept. 11, 2001, attacks had used British airspace or soil.

The agency, which said that neither of the two suspects was tortured or held on Diego Garcia, reviewed rendition records late last year and discovered that in 2002 the CIA had refueled two separate planes.

"The refueling, conducted more than five years ago, lasted just a short time. But it happened. That we found this mistake ourselves, and that we brought it to the attention of the British government, in no way changes or excuses the reality that we were in the wrong," CIA Director Michael Hayden said in a message obtained by The Associated Press.

Despite American assurances, British officials kept pressure on their U.S. counterparts to check all records of rendition flights, according to a British government official who spoke on condition of anonymity because of the sensitivity of the issue.

"We consistently sought reassurances because of the high public and parliamentary interest in this issue," the official told the AP, saying it was not clear what prompted the U.S. investigation.

Washington disclosed that two flights — one bound for the U.S. prison camp at Guantanamo Bay, Cuba, and one bound for Morocco, stopped at Diego Garcia, which Britain leased to the Americans in the 1960s.

It is unclear why Diego Garcia was used as a refueling point.

The British atoll is in the heart of the Indian Ocean and largely cut off to outsiders or civilians. Although it is a British territory, the U.S. base is controlled by Americans and requests to visit the territory are handled by the U.S. government.

At the time of the 2002 flights in question, the United States and Britain did not have an agreement regarding the use of the Diego Garcia facility for renditions, and the refueling stops did not require permission from British authorities, the State Department said.

However, that began to change in 2003 with an "evolving" series of understandings that now require the United States to seek and receive British permission to use Diego Garcia for renditions, spokesman Sean McCormack said.

A "final mutual understanding" appears to have been in place by late 2005, when Rice said the United States respects the sovereignty of foreign countries when conducting intelligence operations within their borders, suggesting that the CIA conducts rendition flights with the permission of the governments involved.

Human rights attorneys and former terror suspects have long alleged that the tropical island is a "black site" prison or secret holding pin for terror suspects. Unlike Guantanamo Bay, few journalists have visited the U.S. base.

The U.S. government has denied holding suspects on Diego Garcia.

Miliband said the U.S. investigation showed no other record of any other rendition through Diego Garcia, other overseas British territories, or through the U.K., but that he had ordered an independent review of flights activists believe were used in renditions.

Britain's main opposition party said the disclosure raised questions about the previous "categoric" assurances from the British government and would undermine public trust in Prime Minister Gordon Brown's government.

"The delay in releasing this information and the evident absence of a request in these cases are bound to undermine public trust, to some extent, in the arrangements which we have with the United States," said William Hague of the Conservatives.

"The efforts of the United States — our most important ally — to fight international terror are essential to the security not only of America but of Britain and many other nations," he said.

Parliament's Intelligence and Security Committee, a panel of lawmakers that meets in private to scrutinize intelligence work, last year investigated Britain's role in rendition.

Though it found no evidence of British complicity in extraordinary rendition, it strongly criticized the government over poor record keeping, saying officials had been unable to quickly search for evidence of rendition requests.

British security officials say discrepancies in records are not uncommon.

"It just happens with bureaucracies that there is bad record keeping," said a British security official speaking on condition of anonymity. "It is clearly not great but if the Americans tell us something, we don't immediately suspect them of lying."

Britain is the first Western European government to directly acknowledge that one of its territories was used in the U.S. renditions and is among 14 countries accused by the European Parliament and the Council of Europe of colluding with the CIA to transport terror suspects to clandestine prisons in third countries.

A European parliamentary report identified at least 1,254 secret CIA flights that entered European airspace after the Sept. 11 attacks.

In a report, it said the flights violated international air traffic rules, and suggested that some may have carried terror suspects on board in violation of human rights.

"The British government has always said that none of the 170 confirmed CIA stopovers at U.K. airports were renditions, because the U.S. always asks for permission for prisoner transfer. We now know that in at least two cases, the U.S. didn't ask permission. How many other times did the U.S. fail to inform the British government?" asked Tom Porteous, Human Rights Watch' London chief.