KUALA LUMPUR (AFP) - New evidence has suggested that communication from the missing Malaysia Airlines flight MH370 may have been deliberately cut off.

ABC news said US investigators now believe the aircraft's data reporting system and its transponder - which reports its position in flight to ground-based radar - shut down separately.

The fact that the devices appear to have been shut off at a 14-minute interval from one another suggests that they may have been deliberately disabled or at any rate did not fail as a result of a catastrophic airframe incident, the US network said.

The transponder was switched off 30 minutes after the final voice communication from the cockpit, around the same time that Malaysia believes the plane may have inexplicably started to turn back, the Washington Post said.

Taken together, that "suggests that someone unauthorised took control of that airplane, like an intruder or one of the pilots", the Post quoted one US flight crash expert as saying.

According to data obtained, the reporting system was shut down at 1.07am (Malaysia time) and the transponder at 1.21am.

The plane lost radar contact at around 1.30am, less than an hour after take-off, according to Malaysian officials.

They have confirmed that the last words heard from the cockpit were a relaxed "Alright, good night" as the plane was due to pass from Malaysian to Vietnamese air traffic control. The night was clear and the weather was fine.

"The last (data) transmission from the aircraft was at 0107 hours which indicated that everything was normal," Malaysian Transport Minister Hishammuddin Hussein told reporters on Thursday.