By Jonathan Kent BBC correspondent in Malaysia

The search operation has come under intense criticism for its failure to find the aircraft a week and a half after it disappeared.

Two senior politicians from the state of Sarawak were onboard, as well as the head of the local electricity company.

After 11 days of fruitless searching, desperation seems to have set in.

Officials have summoned the witch doctors, or bomoh as they are called in Malaysia.

A spokesman said that each had given a different description of where the helicopter had crashed, but all agreed that it was in a valley.

The rescuers say that does not help much as the area where they now believe the aircraft went down is made up of lots of valleys and they have no way of identifying which.

However all the bomoh agreed that some or all of the passengers are still alive.

One who appears to be a better businessman than clairvoyant demanded payment in advance, saying that he would definitely locate the seven missing people.

An earlier suggestion that bomoh be brought in to help deal with evil spirits and genies in the forest had been turned down by the passengers' families, who are mostly Christian.

Rescue row

Those co-ordinating the rescue initially seemed sure that the helicopter had crashed in the Bario highlands - a remote area near Malaysia's border with Indonesia.

But the focus of the hunt has now shifted.

There have been allegations that politicians have hampered the search by insisting that they, not the emergency services, co-ordinate the operation.

The missing include a deputy minister from the state of Sarawak, the head of a local council and the chief executive of the Sarawak electricity supply corporation.