The Russian captain of the sunken, burned-out boxship X-Press Pearl has been arrested in Sri Lanka as a pollution probe continues.

Police said Vitaly Tyutkalo appeared before the Colombo High Court on Monday in connection with the country's Marine Pollutions Prevention Act, according to CNN.

The master was released on bail of LKR 2m ($10,000) and has not been formally charged.

Another court hearing has been scheduled for 1 July.

Singapore-based owner X-Press Feeders confirmed the captain has not been charged and is being supported by company lawyers.

"The crew have all returned negative Covid-19 PCR tests and are out of quarantine and housed in local hotels; the two seafarers recovering from leg injuries remain under hospital care," the shipowner said.

The Sri Lankan government is seeking an initial $40m from the owner after the 2,742-teu X-Press Pearl (built 2020) broke in two and sank on 2 June, following the blaze on 20 May.

The money will cover part of the cost of fighting the blaze on the ship.

The fire is believed to have started in a leaking container on deck.

On 15 June, X-Press Feeders said the vessel's bow and forecastle deck are now submerged, and the forward section of the hull continues to slowly settle on the seabed at a depth of 21 metres.

"There has been no noticeable fuel oil spill, and some minor debris has been collected," the company said.

Grey sheen observed

The shipowner said a grey sheen continues to be observed emanating from the vessel, and discolouration of the sea in and around the wreck remains.

This has been apparent since the vessel's stern became submerged, as remnants of the cargo in the 1,486 containers that were on board were exposed to seawater, X-Press Feeders added.

​The ship was carrying more than 22 tonnes of nitric acid and other chemicals, most of which was destroyed in the fire.

But debris including burned fibreglass, and tonnes of plastic pellets have polluted beaches over a 150 km (81 nautical mile) section of coast.

The vessel is a constructive total loss and is entered with the London P&I Club.