Royal Mail workers recruited asylum seekers to launder stolen benefit books and cheques in a massive fraud operation, a court was told.

Benefit books stolen from Dagenham, Essex, were doctored and cashed within days at village post offices across the North-East and North Yorkshire.

The gang, who included asylum seekers from the Congo and Zimbabwe, had only five days to get the cash before the authorities put a stop on them once they were reported missing.

The postal workers knew where to find the books and cheques, which had been sent out by second class post.

The Inland Revenue recovered over 300,000 cheques that went missing from sorting offices and turned up with inflated amounts inserted, said prosecutor Rod Hunt.

He told Teesside Crown Court: "The London post offices that they were supposed to be cashed at were altered to ones on Teesside, the Yorkshire Dales and the Yorkshire Moors. The alteration was done professionally and speedily."

They were worth about £100,000 and the amount obtained in the Teesside and North Yorkshire area was about £37,000.

The asylum seekers were identified from CCTV shots and fingerprints left on the cheques.

Christopher Dorman-O'Gowan, defending, said: "People in the post office looted the envelopes which were passed on.

"One Congolese asylum seeker, who had been studying law in Kinshasa, was sucked into this because he was expected to exist on a small amount of money allowance a week."

Passing sentence on three men and a woman, Judge Tony Briggs said: "Sentences must deter people from acting in this way. Without people in your position doing what you did no one would have lost anything."

Jean Paul Bokoko, 42, a former political prisoner in the Congo, of Petch Close, Middlesbrough, was jailed for 30 months, Chipo Dhliwayo, 36, of Albert Terrace, Middlesbrough, was given a nine months jail sentence suspended for two years, and Francoise Bolela, 35, of Romney Street, Middlesbrough, was given a two year conditional discharge for two years.

Tshiamala Kadima, 34, of Barking, Essex, was jailed for two years, and Kapitene Debamba, 31, also of Barking, was given a six months jail sentence suspended for two years.

Bolela pleaded guilty to obtaining property by deception and the rest admitted conspiracy to defraud between 13 September last year and March 8.