MI5 has taken the unusual step of issuing a public warning after fraudsters pretending to be the service's head attempted to obtain money from people.
In a message that was posted on MI5's website yesterday, the security service warned that people should not fall for the "financial scams".
It said that people had been asked for money by e-mail and telephone with some correspondence purporting to be from the MI5 Director General, Sir Jonathan Evans.
"These requests are a financial scam and have nothing to do with the service or the Director General," reads the statement on the MI5 website – one of the few updates on the site apart from job vacancies and the United Kingdom's current terror threat.
Anyone who had been contacted was urged to report the scam to police.