Nigerian security agencies have impounded a foreign vessel laden with suspected toxic waste after it berthed at the Lagos Tincan port, officials said Friday.

"We received an alert from the International Network for Environmental Compliance and Enforcement that a ship carrying e-waste and some toxic materials was heading to Nigeria," said senior environmental protection official Ngeri Benebo.

Benebo, who heads the National Environmental Standards and Regulatory Enforcement Agency (NESREA), said all the relevant security agencies, including the navy and port, were put on the alert.

Navy spokesman Commodore David Nabaida said information available after inspection showed that the "containerised ship" carried used batteries and electronics, including television sets.

"There is misinformation. The ship did not carry toxic wastes. It carried used batteries and television sets for resale in Nigeria. The ship's bill of lading also indicated this. And so, the ship's operation was above board," he said.

He did not say why the ship was not inspected when it landed on Thursday.

Benebo had accused port officials of frustrating efforts to inspect the vessel immediately on arrival to determine its actual contents, and said she feared that the container might have been tampered with overnight.

"Port officials said the vessel will be checked this morning, more than 24 hours after the ship's arrival. I only hope that the container suspected of containing toxic waste had not been removed," she said.

According to the Nigeria Port Authority (NPA) the vessel with the registration name Maersk Nashville Hamburg arrived at the Tincan port in Lagos on Thursday.

In 1998, the dumping of toxic waste in Nigerian coastal town of Koko in southern Delta State by an Italian firm, sparked a diplomatic row between Nigeria and Italy.

The substances were later removed after the government evacuated residents of the polluted community.