A second oil tanker may also have disappeared in Nigeria.

Nigeria's navy seized MT African Pride tanker along with 13 Russian sailors, on suspicion of smuggling last October.

But the tanker, laden with crude oil, disappeared last month. Navy and police officials have blamed each other.

Some 30,000 barrels of oil are lost to fuel thieves each day in Nigeria, officials say.

'Disappearing act'

The mysterious disappearance is "an episode that belonged to the old Nigeria," Anthony Aziegbemi , chairman of the parliamentary committee conducting the investigation, said in a statement.

[It's] to say the least, a national embarrassment Anthony Aziegbemi

He said the navy committee is resolved to get to the bottom of the disappearing act.

"The rule of law should catch up with anybody no matter how highly placed," he said.

The defence minister and other naval officers have been asked to appear before the committee this week.

Another ship detained in connection with the alleged theft of oil, the MT Jimoh, might also have gone missing with its cargo of crude oil last week, although this was not confirmed, Mr Aziegbemi said.