The man and woman, aged 60 and 64 respectively, had just taken off from El Questro when their twin-engined Cessna 421 hit the ground and exploded.

A police spokeswoman said the pair were born in Britain but had been living in Australia. Their daughter, who lives in Perth, has been told of their deaths.

A Foreign Office spokesman said details had not yet been formally confirmed.

He told BBC News Online the Foreign Office was waiting to find out more from its consulate in Perth, Western Australia's state capital.

'Turned upside down'

The privately-owned, Swiss-registered plane, which was carrying only the two people killed, came down at noon local time (0500 BST).

Eric Siewert, general manager of the El Questro homestead, said the tourists were leaving after spending two nights at the exclusive wilderness park near the town of Kununurra.

He said: "Just after take-off their left engine failed, we believe.

"It banked to the left and turned upside down and crashed. It was very quick and it exploded."

The aircraft exploded on impact and was consumed by fire Senior Constable Jodie Dilallo

Senior Constable Jodie Dilallo, of the Western Australia Police Service, said: "We spoke to the people at the homestead who said they were English tourists who had been travelling around. I think they had retirement visas.

"The plane took off and started climbing at the El Questro airstrip.

"It banked sharply and plunged to the ground into a field. The aircraft exploded on impact and was consumed by fire."

Peter Hook, a spokesman for Accor Asia Pacific, which owns the resort, said it appeared the pair had been trying to come back to ground with engine problems when they crashed.

Investigators from the Air Transport Safety Bureau are leading the inquiry into the crash.

The El Questro wilderness park extends across one million acres of outback in the Kimberley region of far North Western Australia.

Opened in 1991, it has attractions including wildlife, gorges, thermal springs and rock art sites.