MH370 search vessel clouded by conspiracy

The Seabed Constructor has spent the past two weeks looking for signs of MH370 in the Indian Ocean.
The Seabed Constructor has spent the past two weeks looking for signs of MH370 in the Indian Ocean.

Conspiracy theories have shrouded the ship tasked with finding missing Malaysian Airlines flight MH370, which has docked at a Perth port.

The Seabed Constructor has spent the past two-weeks searching for signs of the missing aircraft in the southern Indian Ocean.

The vessel sparked a flurry of internet chatter last week after it turned off its transponder and disappeared for almost three days from tracking screens.

It appeared to travel in a wide circle before it stopped transmitting its location near the site of a historic shipwreck, leading some on Twitter to speculate it had stopped to pick up a sunken "treasure chest".

The shipwreck was found during a search for the plane in 2015, with a sonar scan detecting a 6m box-shaped object among the debris.

In 2016 Fugro chief executive Paul Kennedy, who heads the Dutch company which led the first MH370 search, revealed a large chest had been found in the wreck's remains.

"It's a big chest, it's about three metres long, maybe one-and-a-half metres wide, and it's still closed," Mr Kennedy said.

There were 661 areas of interest detected in the original MH370 search and four shipwrecks were identified in the largest ever single hydrographic survey of the seafloor.

Seabed Constructor turned its Automated Identification System back on when it headed back towards the West Australian coast.

It docked in Henderson, south of Perth, on Thursday where it will refuel before returning to its 25,000 sq km search area to scour the ocean floor.

US-based company Ocean Infinity has been hired by the Malaysian government to search for the plane, which disappeared in March 2014 while flying to Beijing from Kuala Lumpur.

It has 90 days to find the plane under a no-find, no-fee agreement which could earn the company up to $US70 million ($A90 million).