A piece of debris found on a beach in South Africa will be analysed to see if it belongs to missing Malaysian Airlines flight MH370, authorities said Tuesday, after two other similar finds.

The unidentified fragment was picked up near Mossel Bay, a small town in Western Cape province, the South African Civil Aviation Authority (SACAA) told AFP.

"The necessary arrangements are underway for the evaluation and collection of the part, which, if it indeed belongs to an aircraft, will then be handed over to Malaysian authorities," it said.

The SACAA did not reveal when the fragment was found.

Mossel Bay is over 2,000 kilometres (1,250 miles) from Vilankulo, the Mozambican resort where suspected MH370 debris was found by an American amateur investigator earlier this month.

News of that discovery led a South African teenager to reveal he had found another metre-long fragment on a beach in Mozambique while on holiday with his family in December.

Both those pieces have been sent to Australia for expert analysis.

On March 8 2014, MH370 diverted for unknown reasons while on an overnight flight from Kuala Lumpur to Beijing with 239 passengers and crew aboard.

A wing fragment confirmed to be from the plane was found on the Indian Ocean island of Reunion last year.

Investigators believe the plane rerouted to the southern Indian Ocean, where it crashed.

No crash site has been identified which could help solve the baffling mystery.