By Philippa Busby BBC Radio 5Live Consumer Affairs Reporter

A shoplifting scam is costing retailers tens of millions of pounds a year, a BBC News investigation has discovered.

Thieves are returning stolen goods to shops and claiming cash refunds with fake receipts, a former conman has revealed.

He said the scam earned him up to �5,000 a day.

Shoplifting costs business large amounts of money

Shoplifters might only make 20% or 30% of the retail price if they sold the goods on the black market.

The former conman said: "You get 10 stolen coats, the same style the same size, the same code number.

"All you have to do is go and buy one legitimately, get a cash receipt and you make 10 duplicates and take them 10 times to 10 different shops."

The former conman said he targeted many major High Street stores including Marks and Spencer, Next, Gap and BHS.

You just copy the receipt in a simple machine and you have got a duplicate receipt that you can use again and again Former conman

Forging the receipts takes just a couple of minutes using basic domestic electrical equipment.

A genuine receipt and till rolls are used.

The former conman said: "The paper is easy to get from the shops, either you buy it from the shop assistant or you help yourself to it.

"You just copy the receipt in a simple machine and you have got a duplicate receipt that you can use again and again".

The British Retail Consortium said the scam was costing an estimated �45m every year.

Director of corporate affairs David Smith said the consortium was introducing systems to detect fake receipts.

But Centre for Retail Research director Joshua Bamfield said the problem was far worse than stores would admit and could account for 10% of all retail crime, making it worth as much as �300 million a year.