House repossessions are at their highest level for eight years and the rise is expected to continue, a BBC Wales investigation has found.
Experts say sub-prime lending is contributing to mortgage difficulties
Almost 3,000 possession orders were granted in courts in Wales in the first half of 2007.
Housing industry observers said high property prices and rising mortgage costs will fuel repossession figures.
The Council of Mortgage Lenders predicted that any rise in repossessions would be a modest one.
The Week In Week Out programme looked at the housing market in Wales - where house prices have trebled in a decade - as it is hit by falling property prices and five interest rate rises since August last year.
Mick McAteer, a former policy adviser for Which? and who now heads a think-tank on financial inclusion, said he expects repossessions to be fuelled by a "perfect storm" of high property prices and rising mortgage costs.
He said: "There are a large number of people who are actually quite vulnerable to any change in their financial circumstances.
"The amount of money they owe means that they are at their absolute limit and if they do have a change in their financial circumstances I am afraid they will be tipped over the edge."
The programme found the growth in sub-prime lending - higher-interest mortgages to people with poor credit records - is contributing to those being caught out.
Les Cooper, of Flintshire Citizens Advice Bureau, said as recently as three years ago he would recognise most of the mortgage firms involved in repossession hearings he attended.
June and Ken Purchase were evicted from their home in September
"But now when I go to court and I look at the listings, there are huge numbers of sub-prime lenders in almost the majority of the listings," he said.
"And there are companies there I've never heard of. They are popping up like mushrooms."
The programme found that, taking into account their market share, sub-prime lenders repossess 10 times more properties than high street mortgage companies.
June and Kenneth Purchase were evicted from their home at Llanharan, near Bridgend, in September.
Two years ago they re-mortgaged their house with a sub prime lender. They also took out a loan for £25,000 with another sub-prime lender, not realising that the total they would have to repay would be £59,000.
'Arrears and possessions'
When interest rates went up they began to struggle, and when Mr Purchase lost his job they could not meet their mortgage and loan repayments.
Mrs Purchase said: "At the end of the day, it's not that we didn't want to pay the mortgage - it just went, just spiralled out of control."
The programme reports that in 2006, Citizens Advice Bureau in Wales saw 20% more debt cases than in 2005. The total amount owed was £76m, much of it to sub-prime lenders.
Bernard Clarke, of the Council of Mortgage Lenders, said the organisation was looking at "sub-sectors of the market" to predict possible repossession figures.
He said: "We would expect there to be a rise in arrears and possessions, but it will be, we hope, a relatively modest rise in arrears and possessions.
"We don't think we are going back to the circumstances that we saw for instance, in the early 1990s."
Week In Week Out is broadcast on Tuesday 23 October at 2235 GMT on BBC1 Wales and repeated on Thursday 25 October at 2130 GMT on BBC2W