This is the size of more than 500 football pitches.

It follows last Wednesday’s explosion of an oil production vessel - the Trinity Spirit - that had a storage capacity of two million barrels, though it was not believed to have been storing that much. Three people died in the blast.

Idris Musa, head of Nigeria's National Oil Spill Detection and Response Agency (Nosdra), told the BBC's Newsday programme that chemical dispersants had been applied to reduce the damage to marine life in the area.

The location of the spill was not far from where the Trinity Spirit caught fire, he said.

When asked if the government body could deal with slick effectively, Mr Musa replied: “Certainly we can, certainly we can.”

However, cynics will note that many previous oil spills in Nigeria have not been cleared up.