The four men fed plastic coated £20 and £50 notes into betting slots in order to register a deposit for a wager, before using a plastic lead to yank the note back out before it was taken.

Thomas Wheatcroft, 40, Charlie Shaw, 33, Michael Sadgove-Tarrant, 37, and Paul Hubbold, 59, committed 168 frauds by travelling the country targeting different betting shops.

Ladbrokes and Coral stores across the UK, including in London, Yorkshire, Merseyside, Essex, the West Midlands, Cambridgeshire and Surrey were all conned between last July and June this year.

Staff called police when they noticed thousands of pounds were missing during the cashing up of the machines at the end of the day.

CCTV from different shops showed the group responsible for the thefts had been wearing the same clothing.

When cops arrested Wheatcroft, Shaw and Sadgove-Tarrant in Basildon, Essex, they found bags of clothing that included 20 baseball caps.

So far the total loss to Ladbrokes and Coral has been calculated as £663,556, police said.

At Kingston Crown Court on Monday November 22 all the defendants pleaded guilty to conspiracy to commit fraud and were handed life-time bans from going into any bookmakers in the UK.

Wheatcroft was jailed for four years and three months and Shaw was handed a two-year jail term, while Sadgove-Tarrant was sentenced to one year in prison, but suspended for two years.

All the defendants are from Portsmouth except for Hubbold, of Barrow-in-Furness, Cumbria, who was given a prison term of nine months, suspended for 18 months.

Detective Constable Kevin Parley of the Met Police, who worked on the case, said: "The substantial sums of money stolen by the group is a significant loss to the businesses these men had targeted.

"We worked closely with security officials from both firms to carry out a joint investigation, which included gathering evidence to bring forward a robust case against the four men.

"I am pleased that Wheatcroft and Shaw, who were the main offenders, received custodial sentences, and I hope this provides some relief for the companies who have been affected by their actions."

Gang of fraudsters conned bookies out of more than £600,000 using laminated money to trick self-service machines