Shhhhhhh. What's the UK's most secret organisation? One mysterious outfit will not reveal the name of either its head honcho or location and appears to have no website.

We can reveal it's not M15. The Security Service is headed by Eliza Manningham-Buller and is based in London's Thames House.

But could it be MI6, also known as the Secret Intelligence Service? No, this body which protects our interests by gathering evidence from outside the UK has John Scarlett at its helm and offices in Vauxhall Cross. The plot thickens.

But, the answer for all you mystery lovers is...the Insurance Fraud Bureau.

Royal & SunAlliance's fraud guru John Beadle is the bureau's chairman, while AXA's Richard Davies acts as his deputy. But, who will actually be running the whole shebang? It's known the bureau's top job was advertised and, rumour has it, an appointment has been made.

Beadle's lips are sealed. "We can't divulge this information at present. The people in the bureau need to remain anonymous," he said. Given that insurance criminals are a nasty bunch, such discretion is to be applauded.

But since insurance folk are such a gossipy crowd, no doubt someone will come in from the cold and spill the beans.