An investigation claims lenders of sub-prime mortgages make up more than 70% of all repossession hearings - despite only accounting for 8% of the UK market.

The study by Panorama and the Five Live Report into the industry also found some council tenants on benefits are being told to exaggerate their income to take part in "right to buy" schemes.

Sub-prime mortgages are often given to people with poor credit ratings who otherwise would not be able to get a home loan.

The global "credit crunch" which affected Northern Rock was caused by the collapse of the American sub-prime market.

David and Maureen Bradbury, who are in their 50s, were given a 25-year mortgage worth £55,000 by London and Scottish Bank.

With their interest rate at more than 11%, the couple, who are on benefits and in poor health, struggled to make repayments.

They said they bought their council house so they could pass it on to their children, but Mr Bradbury told the BBC: "I'm at the mercy of the interest rate. If it goes up again, I'll struggle, I'll try and meet it.

"But after that if it goes up again I can't. We'll just lose the house."

London and Scottish said it follows industry regulations regarding responsible lending.

The broadcaster also found that many banks and building societies sell bundles of mortgages on for cash.

But if increasing numbers of these are mis-sold to people, whoever is left holding the debt could suddenly find it worthless - a problem which affected various companies in the US.

The Council of Mortgage Lenders has welcomed the research as it believes not enough is known about repossessions among sub-prime borrowers.

The BBC survey obtained the court lists of repossession hearings at 28 county courts across England, Wales and Northern Ireland during the last three months.

These hearings do not always result in a repossession as the lender and borrower could reach an agreement.

The survey covered lenders who specialise in sub-prime deals, and those with both sub-prime and prime borrowers.

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