French debt collectors are pursuing the families of two snowboarders who died in an avalanche last year.

Rescuers failed to save the two, who were boarding off-piste at about 3,200m on the north face of La Grande Motte, near Tignes. Now their families face a bill of £20,000 for the rescue effort.

James Rourke and Sam Harber had taken out insurance for rescue costs, but the company refused to pay out because they knew in advance that the avalanche risk was category three – considerable – and their policy excluded claims for exposure to danger which is reasonably foreseeable.

The company involved in the rescue has engaged debt collectors to chase the £9,000 due for the helicopter and £1,200 for the dog teams.

Barry Harber, father of Sam, whose body was found two months after the incident, on what would have been his 26th birthday, said he wanted to warn others about the loophole in their insurance policies. “There must be hundreds of kids going out there thinking they’ve got cover off piste.

“The rescue teams did such a good job and deserve to get paid but there is this massive grey area when it comes to this kind of insurance.”

Sam and his friend James, 26, were buried when the avalanche broke100m above where they were boarding. The pair were working as ski chalet managers in Val d’Isère. Jean-Louis Tuaillon, director of the Tignes Piste Service, said at the time of the accident that the avalanche was due to bad luck rather than any particular error by the men.

The families of both men have vowed to fight the attempt to recover the debt, despite losing two attempts to take the case to the Financial Ombudsman.

Rescue services in Britain are free and provided in the main by unpaid volunteers with support from helicopters from the armed forces, though the Government has plans to put the search-and-rescue helicopter service into private hands in 2012, as reported here on grough.