COLOMBO • A Sri Lankan court hearing into the fire and sinking of a container ship off Colombo was told on Monday that its local agent had deleted e-mail vital to the investigation.

The Singapore-registered MV X-Press Pearl reported an onboard acid leak to its representative Sea Consortium Lanka, which in turn failed to alert the local authorities, said the state prosecutor.

He said investigators found that Sea Consortium had wiped its e-mail with Russian skipper Tyutkalo Vitaly. "The magistrate ordered the local agent (of the ship) to provide the originals of the e-mails from mail servers located abroad," said a court official.

Magistrate Chalani Perera also ordered the Sri Lankan navy to protect the wreckage lying submerged just outside the Colombo port.

The Sri Lankan port authorities had said they were unaware the vessel had been leaking nitric acid since May 11, nine days before the fire started in Sri Lankan waters.

Sri Lanka's navy recovered the ship's black box over the weekend. The Voyage Data Recorder, also known as a maritime "black box", was found intact and is expected to help investigators review procedures and instructions ahead of the disaster.

The Sri Lankan authorities hope it will provide details of the ship's movements and its communications with the Colombo harbour, where it had been due to dock.

The Sri Lankan police launched a criminal investigation, interviewing Mr Vitaly and his chief engineer Sadilenko Oleg and chief officer Peter Anish, an Indian.

The authorities are bracing themselves for a possible oil spill from the submerged wreck. However, there has been no sign of any leaks so far, they added.

Tonnes of microplastic granules from the ship swamped an 80km stretch of beach declared off-limits for residents.

Sri Lankan environmentalists last Friday sued the government and the ship's operators for allegedly failing to prevent what they called the "worst marine disaster" in the country's history.

AGENCE FRANCE-PRESSE