A charity whose chairman helped free 226 Christian hostages from Isis is being investigated by the Metropolitan police on suspicion of paying ransom money that financed terrorism.

The Assyrian Church of the East Relief Organisation (Acero) came under scrutiny when it stated in its accounts that it had paid £147,689 for “Iraq Hostages”.

NatWest has frozen almost £500,000 in the charity’s bank account and the National Terrorist Financial Investigation Unit has seized its records. The Met said it was investigating “to determine if terrorist financing offences have been committed”. The Charity Commission said it was “examining serious concerns about the governance of Acero and its activities overseas”.

While the charity is run by Andy Darmoo, 71, who operates a chandelier business in Kent, its chairman