Kuala Lumpur - Plane debris washed up on an island off the eastern coast of Africa was being tested on Thursday, as speculation grew that it could come from missing Malaysia Airlines flight MH370.

The Beijing-bound flight, with 239 people aboard, disappeared on March 8 last year, about an hour after it took off from Kuala Lumpur International Airport.

The Australian minister in charge of the underwater search for the plane said it was a "realistic possibility" that the wreckage washed up on Reunion Island was from the missing aircraft.

Australian authorities were reacting to the find as a "major lead," Deputy Prime Minister and Transport Minister Warren Truss told a press conference.

Reunion Island is a French territory east of Madagascar, over 5 000km from the area where a vast Australia-led search for the plane is taking place.

The plane was thought to have crashed into the Indian Ocean, but its exact location and the reason for its disappearance is a mystery.

A Malaysian government team was being sent to Reunion where the 2-metre-long piece of debris was found, covered in small shells.

A Malaysian Transport Ministry official, who wished not to be named, quoted government experts as saying it was "nearly certain" that the part came from a Boeing 777, the same type of plane as MH370.

However, the ministry said in a statement that "until there is tangible and irrefutable evidence" it would be "premature to speculate" about the origin of the debris.

"This is to ensure that we do not raise false hope for the loved ones of the victims of MH370," it added.

Maintenance number

Truss said that a number found imprinted on what appears to be a wing flap, called a flaperon, was not a serial number or registration number, but it may be a maintenance number which could help identify where it came from.

Truss said marine biologists in Australia are also examining photos of the barnacles on the two metre long flaperon to see if it could have been in ocean water for the 16 months since the flight disappeared with 269 people on board.

Malaysia Airlines said earlier on Thursday it was too early to tell whether the debris came from MH370.

"Malaysia Airlines is working with the relevant authorities to confirm the matter," the company said in a statement.

"At the moment, it would be too premature for the airline to speculate [on] the origin of the flaperon," it added.

Citing a source close to the investigation, US-based broadcaster CNN reported that officials from manufacturer Boeing made an initial assessment that the part found on Reunion appeared to be part of a wing from the company's 777s.