The search for the missing two members of the 53-strong group is continuing. A 19th body was recovered late on Wednesday, but police are not expecting to find the two missing people alive.

The Swiss authorities have suspended all canyoning expeditions until the investigation is complete.

Canyoning is considered dangerous even in good weather conditions

An inquiry has begun into whether the Swiss holiday company Adventure World, based in nearby Wilderswil, was negligent in sending out a party just as a storm was brewing.

They were all part of a group of 45 tourists and eight guides hit by a sudden flood in the Saxeten Bach Gorge near the resort of Interlaken.

Adventure

The group had been canyoning - an adventure sport which involves climbing down gorges and body surfing down mountain rapids and waterfalls without a raft.

The BBC's Caroline Wyatt: "Calls are being made for more checks on the sport"

Police have not identified the dead but said they came from Australia, New Zealand, the UK, South Africa and Switzerland, and included four women.

Australia's consul-general in Geneva, Malcolm Skelly, told Australian radio from Switzerland that the bulk of the tourists involved in the accident were Australians and New Zealanders.

The police said it would take "days or weeks" to identify all the victims, and appealed to relatives of the dead and missing who were planning to come to Switzerland to bring dental records, X-rays or any other material that could help identification.

Condolences

The Swiss Government sent its condolences to the victims of nature's "wild behaviour".

Five of the six survivors were released from hospital on Wednesday.

Ann Hall tells how her son's friends died in the disaster

The BBC's Caroline Wyatt in Interlaken says eyewitnesses reported that the waters of the Saxeten brook rose rapidly as the storm gathered force.

A flash flood brought down a hail of rocks from the sides of the creek. The waters rose several metres above their usual level, leaving most of the canyoners with little hope of escaping up the steep sides of the gorge.

The authorities have set up a special phone line for worried relatives on (41-31) 634-20-51.