Immigration officers have prevented 70 sham marriages from taking place in just one month at a busy city centre register office.

Border Agency staff spent four weeks interviewing everyone getting married at Leeds register office, which uncovered a high number of sham ceremonies.

The BBC's Inside Out Yorkshire programme followed the officers, filming them bursting in on two services involving men living in the UK illegally.

In the first operation, officers swooped on a wedding between a French bride and an Indian groom whose leave to remain in the UK had been revoked. A second wedding between a Pakistani man and a Lithuanian woman was also halted.

Detective Inspector Adrian Watkins, from the UK Border Agency, said: "Certainly since we started looking at these last March, there's been an increase and they've been brought to our attention on a more regular basis, probably because the registrars themselves are more aware of the problem."

Church officials also have to look closely at who is getting married.

The rector of Leeds Parish Church Canon Tony Bundock said: "Because of some of the abuses that did take place a few years ago, we're now required to check that the address that they've given us is genuine by actually visiting them, going to both houses, both the bride and the groom.

"Also we're required to check their identity by seeing some documentary evidence that proves that they are who they say they are."

The 70 sham marriages were prevented over two separate fortnights towards the end of last year, said a BBC spokeswoman. The two services which were interrupted by Border Officials and caught on camera happened at the end of January.

The documentary will be shown at 7.30pm on Monday on BBC One in the Yorkshire area and on the BBC iPlayer.