The number of cars voluntarily given back to banks by stressed borrowers unable to meet monthly loan payments has spiked dramatically, according to the country's largest auctioneer of repossessed cars.

David Byrne, managing director of Merlin Car Auctions, said up to half of the 1,000 cars it sells a week are former finance cars sold by banks. But more car borrowers are surrendering their cars rather than waiting for them to be repossessed, Byrne said.

"I think there is a huge number of people handing back their cars. Of the 200 [finance] cars sold, 100 would be surrenders, which was not the case a year ago," he said.

Byrne said he expected "in time" to see a drop in the number of surrendered or repossessed finance cars coming through to auction, as fewer new cars are sold.

The company sells more than 90% of the cars that borrowers in Ireland have returned, voluntarily or involuntarily, to their lenders.

Byrne said its most expensive former finance cars include top-of-the-range Porsche Cayenne Jeeps and Range Rovers, which were worth up to €90,000 new.

The most expensive repossessed car it has sold was a €300,000 Bentley Continental which was auctioned last year for €125,000.