The list was given to the Security Council's al-Qaeda and Taliban Sanctions Committee on Wednesday, a UN spokeswoman confirmed yesterday.

Iran has been accused by US officials of harbouring al-Qaeda members and allowing them to operate from Iran. This has been denied by Tehran, which aims to prosecute some of those it is holding on charges of planning terrorist attacks inside Iran.

An official said Iran had decided to give the names to the Security Council because some countries refused to accept the repatriation of their detained nationals. He said Iran had deported 400 former Taliban or al-Qaeda fighters, who had crossed from neighbouring Afghanistan since the US-led war that overthrew the Taliban regime. Most had gone to the Gulf states, the official said.

Iran has arrested 2,300 people since October 2001, the official said. It is unclear what has happened to those who were no longer being held and had not been deported.

"Some of these al-Qaeda people were helped to come to Iran by Pakistani officers," the Iranian official said. "The ones we are holding must be kept in Iran for some time, as some will go on trial for planning acts against Iran."

Evidence that al-Qaeda leader Osama bin Laden's deputy, Ayman al-Zawahiri, visited Iran in 1998 has led some US officials to suggest that the terrorist network has ties with Iran.

UK officials reject this, saying that Iran's public suspicion of al-Qaeda is genuine.

"Al-Qaeda isn't a problem that Iran wanted to have wished upon it," said one official. "Iran is almost as much of an enemy for al-Qaeda as the west. Up to a point there is a genuine Iranian wish to see al-Qaeda dealt with."

Some analysts and western intelligence officials say that officers within the al-Quds Brigade of Iran's Revolutionary Guard Corps were protecting al-Qaeda activists, possibly including Mr Bin Laden's son Seif.