Six days after the disaster which it is thought may have killed up to 40,000, Ray Gray told BBC Radio 4's Today programme some people could still be alive under the collapsed buildings, even though the rescue operation was being wound up.

"There are...around 35,000 people still unaccounted for. Some may be elsewhere in the country and people just don't know where they are, but some will definitely be in buildings," said Mr Gray.

One or two still alive

"A large percentage of them will not be alive. There may well be one or two of them that are still alive but the conditions that they were trapped in, the type of collapses within the buildings and the temperatures up in the 115-120 degree mark will mean people will not be surviving for much longer."

He admitted that as bulldozers took the place of rescue teams, it was possible that these last survivors would die.

"It is possible, yes. From our point of view we are confident there are no survivors in the buildings where we worked, but we only worked in a very small area on a very large-scale disaster," he said.

Mr Gray said that his team had decided to leave after consultations with the Turkish interior ministry, and other rescue teams were preparing to leave in a phased pull-out.

Role diminishing

He did not feel that the team was leaving prematurely.

"We are very much a short-phase search and rescue team," he said. "We were there 24 hours after the earthquake, very early on Wednesday morning.

"We felt our role was starting to diminish to the degree that it was right for us to withdraw and it was time for the medium-term and long-term people to start taking over."