Listen very carefully, because I will say this only once A highly-covert team of super-secret spies has taken up residence in the heart of Bradford, and could be walking among you even as you read this.

Official sources are remaining tight-lipped, but it is understood that a film and television production company with the codename "Kudos" has commandeered the former police station at the Tyrls off Centenary Square.

They are believed to be filming a spin-off series from the popular BBC1 spy drama Spooks, featuring a younger cast and set in the "near future", possibly around the time of the 2012 Olympics, when a terrorist nuclear attack on London has wiped out the secret service's headquarters at Thames House.

It is left to a team of rookie agents "who don't play by the rules" to take over Britain's security work. The Tyrls is thought to be doubling for their headquarters in Manchester.

Names linked to the project include hot young British talent such as Joanne Froggatt, who recently appeared in Life on Mars and before that Coronation Street; Liam Boyle (The Street, The Bill); Georgia Moffett, who is the daughter of Peter Davison and Sandra Dickinson; Ruta Gedmintas (The Tudors); Christopher Simpson (the West Yorkshire-set movie Mischief Night) and Andrew Knott, who was in the movie version of Alan Bennett's play The History Boys.

The main series of Spooks, starring Peter Firth as MI5 boss Harry and Rupert Penry-Jones as troubled agent Adam, has run to six series so far. The spin-off is expected to be aired this year on BBC3 and is aimed at a more youthful audience.

When the Telegraph & Argus approached Kudos we were met with a wall of silence. However, after making representations that the story was a matter of public interest, the T&A did get a brief chat with one secret source.

The not-so-Deep Throat revealed: "At the moment the series is called Spooks: Liberty, but that is just a working title. We won't be able to say what it will be called until details have been approved with the BBC."

The series has also had a previous working title, called Rogue Spooks. When asked if we could have access to the filming at the Tyrls we were told: "Absolutely not. It is a completely closed set. I'm afraid we can't confirm or deny anything about it at the moment."

The major player in this story seems to be the "BBC", which is understood to be a quasi-autonomous public corporation, funded from the public purse via central Government control.

A spokesman for the organisation said: "We haven't really got any press material for the new series yet because it's still in production."

However, documents classified as Above Top Secret and obtained by the T&A (okay, found on the floor of the NCP car park on Hall Ings) reveal certain details about the production, including the facts that the agents' headquarters in the Tyrls are designated "MI5 Field Office 19", one episode features a scene in a massage parlour and a university study hall, where someone gets shot in the head, and there is no smoking, eating or drinking on set at any time, although breakfast is generally about 7am.

More details will follow as our investigations continue.

Meanwhile, this news story could self-destruct in five seconds e-mail: david.barnett @telegraphandargus.co.uk