Underwater search for MH370 continues

As the 13th underwater search for Malaysia Airlines flight 370 begins, authorities have yet to find any signs of the wreckage despite examining almost all of the search zone.

The autonomous underwater vehicle, Bluefin-21, has so far searched 95 per cent of the focused underwater search area - a 10 kilometre radius around the second towed pinger locator detection from April 8 - with no significant results.

Up to eight military aircraft and 10 ships are assisting in Friday's search, covering about 49,240 square kilometres, about 1584km northwest of Perth.

Isolated showers are expected with south-easterly winds up to 25 knots, sea swells of two to three metres, and visibility of one kilometre in thunderstorms and three kilometres in rain.

Meanwhile, Malaysia will release a preliminary report on the disappearance of flight MH370, Prime Minister Najib Razak said.

"I have directed an internal investigation team of experts to look at the report, and there is a likelihood that next week we could release the report," Razak told CNN in an interview aired late on Thursday.

The government has so far been tight-lipped about its investigation into the disappearance of the jet, sparking anger among the relatives of the 239 people aboard the plane about the government's level of transparency.

The Boeing 777 vanished on March 8 en route from Kuala Lumpur to Beijing.

AAP