An Iranian nuclear scientist allegedly abducted by the CIA was flying back to Tehran after seeking refuge at the Pakistani Embassy in Washington.

Shahram Amiri disappeared on a pilgrimage to Saudi Arabia in late May last year. Iran claims he was taken to America against his will but American authorities have dismissed that as "ludicrous", while hinting he had defected and was providing information about Iran's covert nuclear weapons programme.

Amiri has backed both sides of the story on conflicting videos on YouTube.

Yesterday he told Iranian state television by telephone that the US Government had been trying to return him to Iran "quietly".