Iraq-born Tory MP Nadhim Zahawi has said that local leaders in northern Iraq estimate that between 500 and 700 Britons are fighting with the Islamist militants.
He told Channel 4 News that he was seeking further information after a high-ranking official told him one had been found "with a Liverpool Football Club membership card" and another carrying a different UK-related membership card.
Kurdish Peshmerga fighters have emerged victorious in the battle for Mosul Dam, but the question is - what will their next move be?
An ITV News team at Mosul Dam was with victorious Kurdish Peshmerga fighters at the complex earlier today.
ITV News joined a Kurdish unit fighting Islamist militants near Irbil and found them using tanks from the 1950s and short on ammunition.