U.N. special investigator Manfred Novak said detainees were held on the atoll between 2002 and 2003, a claim that raises questions about whether the British government was involved in the practice of extraordinary rendition, The Observer reported Sunday.

Novak, who is charged with investigating human rights abuses, said he had spoken to people who had been held on Diego Garcia, which is also home to a U.S. military base.

"There were only a few of them and they were not held for a long time," the newspaper quoted him as saying.

In 2004, then-Foreign Secretary Jack Straw told Parliament there was a detention center on Diego Garcia. Last month, Foreign Secretary David Miliband admitted two U.S. planes carrying rendered suspects had landed in Diego Garcia in 2002.

Even so, the British government continues to deny allegations that the island, part of the British Indian Ocean Territory, has been used to detain terrorist suspects.