John Carter was jailed for more than four years

The men, from Ely in Cambridgeshire, were sentenced along with three people from Eastern Europe.

The operation involved more than 250 illegal workers at farms and food processing plants across the UK.

Judge Peter Jacobs on Friday jailed David Mutch for six years, Ruslan Kulish for seven years and John Carter for four-and-a-half years.

Mutch, 58, of Soham, Carter, 58, of Caldecote, and Ukrainian Ruslan Kulish, 28, of Ely, ran a gangmaster operation which detectives said brought in more than �100,000 a month for nearly three years.

King's Lynn Crown Court heard the scam generated more than �4m in 33 months - and the three men at the helm shared out profits of �1m.

Ruslan Kulish owned several houses

Detectives said the trio running the operation laundered fortunes by buying seven properties and stashing cash in 30 different bank accounts.

Police said the gangmasters also cheated the taxman out of more than �1 million by failing to pay national insurance contributions or income tax on behalf of their immigrant labourers.

After a seven-week trial Mutch, Carter and Kulish were convicted of concealing or transferring the proceeds of criminal conduct.

Mutch was also convicted of conspiring to use false Home Office documents and processing false documents.

Other sentences

Latvian Veronica Linuza, 27, who also lives in Ely and Viktoriya Kulish, 24, each received jail terms of two years and nine months in connection with the case.

The court heard they were not directly involved in Ultimate Source but both knew where the money was coming from.

Ukrainian Denis Lyashkov, 27, convicted of concealing or transferring the proceeds of criminal conduct and deception, was given a three year sentence.