The firm that operates the vessel which illegally shipped arms to the Apapa Port in Lagos, South West Nigeria, has said that the vessel was loaded in Iran by an Iranian trader.

Cma Cgm, which operates the Marshall Islands-flagged vessel says that the shipment in question was booked as a 'shippers owned container' and supplied loaded and sealed by the shipper, an Iranian trader who does not appear on any 'forbidden persons' listing.

"The shipment in question was booked as a 'shippers owned container' and supplied loaded and sealed by the shipper, an Iranian trader who does not appear on any 'forbidden persons' listing," said CMA CGM.

Cma Cgm, based in France, said the containers were loaded in Bandar Abbas, a southern port city of Iran, and discharged in Lagos in July.

Last week however, the shipper asked to have the containers reloaded and sent to the Gambia.

Cma Cgm adds that clearance had been obtained before Nigerian customs intervened and halted the shipment.

The shipping company insists that it has been cleared of any involvement in the illegal shipment and called itself the "victim of a false cargo declaration."

The ship's last port of call before arriving in Nigeria was India's Jawaharlal Nehru Port near Mumbai.

The vessel berthed in the Nigerian Port on July 10 and sailed out on the 15th of July.

Customs spokesman, Mr Wale Adeniyi says ten of the containers opened so far contain an array of weaponry, despite being declared as building materials.

"Certainly security at the ports has been beefed up and we are trying to move up ahead ... and tighten our own systems to block such shipments," Adeniyi told pressmen.

"Regarding paperwork for the shipment that contained the weapons, Adeniyi said "the documents were irregular... and we felt that the names given on them were false."

"Precise quantities of the weapons will be known after all the containers are opened, he said.

"So far, the 10 examined contained "similar contents -- mortars, grenades, light ammunition and of course tiles," said Adeniyi.

Two people have reportedly been arrested in connection with the cargo, but security officials have not confirmed the reports.

Security agents this week intercepted 13 containers declared as building materials and discharged from the CMA CGM Everest vessel at the port of Apapa in Nigeria's economic hub of Lagos.