Rescue teams found no one alive when they reached the wreckage of a Kenyan Airways plane which crashed in swampland in southwest Cameroon with 114 people on board.

"There are only dead, no survivors," said one relief worker, who declined to be identified.

"There are many mutilated bodies buried in the mud," he added.

A Kenya Airways official earlier said that there was practically no chance of anyone being left alive after the crash.

He said that an airline employee who had reached the scene saw that the nose of the Boeing 737-800 was half-buried and remains of the tail section were scattered over about one kilometre.

Part of the wreckage was in a swamp and part was floating on top of it, Kenyan government spokesman Alfred Mutua said, relaying reports from Kenyan officials in Cameroon.

He said Kenyan Transport Minister Chirau Ali Mamakwele was knee-deep in mud when he visited the site of the crash on May 6.

"It is in the middle of nowhere," Mr Mutua said.

Flight KQ507 vanished from radar screens in a violent storm shortly after it took off from Douala on its way to Nairobi.

The wreckage was found some 36 hours later 20km southwest of the Cameroonian city.

Dozens of villagers armed with machetes helped cut an emergency path to the wreckage, as Cameroonian troops cordoned off the area.

Forensic experts were due to arrive at the site soon, a Cameroonian official said.

The exact sequence of the crash remained unclear, although the Kenyan civil aviation official said the six-month-old plane may have been hit by lightning.