A crude tanker was sub chartered to BP when it was detained amid allegations of oil theft, the company confirmed on Wednesday, as it revealed it was “supporting” owners as they seek the release from Nigeria of its 26-strong crew.

The 300,000-dwt Heroic Idun (built 2020) was detained while it was scheduled to load a cargo of crude from the Akpo terminal off Port Harcourt, said the company in its first public statement since the crew were charged with offences that carry potential life terms.

The Nigerian Navy claims that the Heroic Idun headed to the oilfield without any form of authorisation or clearance. But BP said that the vessel had been cleared “by the terminal before she arrived to load the cargo”.

An initial inquiry report by the Nigerian authorities recommended that officials from BP are invited for questioning. BP did not say if it had spoken with Nigerian authorities about the case.

“BP has been following the case of the Heroic Idun and the plight of her crew,” said the company in a statement. “While we do not own the vessel or employ the crew, we are supporting the vessel owner where we can.”

The dispute over the details of the loading on 8 August prompted the Nigerian navy to send one of its patrol vessels to investigate.

Crew of the Heroic Idun mistakenly believed it was a potential piracy attempt and left the area as a precaution, say representatives for the ship.

Nigeria says the Heroic Idun attempted to “evade arrest” and tried to deliberately collide with the patrol vessel as it escaped Nigerian waters.

The VLCC was later detained by the navy of Equatorial Guinea, which held the ship and crew for nearly three months before returning them to Nigeria for further investigations.

The 26 crew remain on bail on board having been charged with falsely raising a piracy claim and attempting to export oil without authority.

The Ray Car Carriers-owned VLCC could be forfeited to the government if the charges are proven. A provisional trial date has been set for 10 January, said lawyers representing the crew.

The owners, insurers, unions and managers of the vessel have appealed to the International Maritime Organization to help secure the release of the ship and crew.