Debris believed to be part of a Boeing 777 jet has been found off Mozambique and will be taken to Australia to be examined by investigators involved in the search for the missing Flight MH370, Malaysia's transport minister has said.

Liow Tiong Lai said there is a "high possibility" the piece of debris belonged to a 777 jet but added he could not yet conclude that it was from the missing Malaysia Airlines jet.

An official in Mozambique's foreign ministry said the fragment was being flown to the capital Maputo from Inhambane province, 800km to the north, and would arrive this evening.

It would be examined in Maputo by Malaysian and US experts, the official said.

Earlier, NBC News said the piece could be a horizontal stabilizer from a Boeing 777, citing US, Malaysian and Australian investigators who looked at photos of the debris.

The piece of debris was discovered off the east African coast between Mozambique and Madagascar.

Flight MH370 disappeared two years ago when it was en route to Beijing from Kuala Lumpur. Last year authorities found a piece of the plane's wing on the shore of Reunion island in the Indian Ocean on the other side of Madagascar.

"It is yet to be confirmed and verified....I urge everyone to avoid undue speculation as we are not able to conclude that the debris belongs to MH370 at this time," Mr Liow said on his Twitter account.

Flight MH370 disappeared on 8 March 2014, with 239 passengers and crew on board, and is believed to have crashed in the Indian Ocean.

An initial search of a 60,000 sq km area of sea floor has been extended to another 60,000 sq km.