COASTGUARDS were alerted in the early hours of yesterday morning after a barge capsized 30 miles off Harwich, dropping its load of 20,000 tonnes of granite.

The granite was lost overboard after the 122 metre unmanned barge being towed by the tug Hibernia ran into trouble.

Crew on the Hibernia radioed for help at 1.45am reporting that the barge had capsized

A coastguard spokesman said: “The contents of the barge some 20,000 tonnes of granite blocks were lost overboard.

“Thames Coastguard informed Trinity House and the Coastguard Duty Counter Pollution and Salvage Officer, who are monitoring the situation.”

The tug was due to tow the barge to shore this morning.