Counter-terror police investigating large-scale fraud linked to UK extremists travelling to Syria have arrested two men on suspicion of money-laundering.

The arrests are linked to reports of vulnerable and elderly victims being “cold called” over the phone by a suspect impersonating a police officer, who informs them their bank account has been compromised, Scotland Yard said.

Victims are then tricked into transferring money to an account under the control of the suspect, with one elderly victim losing around £150,000.

The men, aged 29 and 23, were arrested at addresses in west and east London respectively and are being held in custody in a police station in south London.

Officers also executed search warrants at two addresses in north London, one in west London and one address in south east London.