Experts are to be called in to help identify a wreck discovered in the River Foyle believed to be a World War II submarine.
Northern Ireland's Environment Minister Alex Attwood has said diving at the discovery site near the Foyle Bridge will be banned until the wreck is positively identified.
It is understood that the wreck is in quite low water and is easily accessible so the Minister wants to ensure that the wreck is not disturbed.
It is believed that there may be munitions on board and possibly bodies of servicemen.
The official dive investigation is due to begin shortly.