A major search operation of cargo is under way in Belfast Harbour today.
The search is being carried out in a joint operation by harbour police and the PSNI. The cargo arrived on a ship at the weekend, a police spokeswoman said, adding that the ship had now left Belfast.
The search is taking place at a warehouse at Gotto Wharf, which has been sealed off. It is believed the search operation began on Sunday after the cargo of steel plate arrived on a vessel from a European port. The warehouse, has been surrounded by 12ft high screens.
Reports have suggested that police were investigating a possible attempt by loyalists to smuggle arms into Northern Ireland.
But the spokeswoman refused to comment on the nature of the operation. No arrests have been made.