DEFENCE chiefs should have alerted the public sooner to the radioactive spill from a nuclear submarine because people swam off Devil's Point during the next few days, a leading scientist has told The Herald.

Dr Colin Trier, a senior lecturer in the environmental science programme at the University of Plymouth, has criticised the Ministry of Defence and Environment Agency for failing to sound the alarm.

He said he knows someone, part of an 'informal group' of swimmers, who takes a daily dip in the River Tamar close to where the spill occurred.

Although the MoD said the environmental risk was 'negligible', Dr Trier said: "People have been potentially exposed to radioactivity without being informed – and that's outrageous."

Up to 280 litres of water, likely to have been contaminated with the radioactive isotope tritium, poured from a burst hose as it was pumped from HMS Trafalgar on November 7. The public only found out when the media broke the story on November 11.

Plymouth City Council has also complained it was not told about the leak.

Dr Trier has called for a policy change and said: "The delay in informing the public prevented us from making decisions about whether it was safe to swim.

"Between the spillage and the Tuesday (November 11) they swam off that point. We have a right to know and there is no reason not to be told quickly.

"There's a case for asking serious questions about why there was a delay. We have not seen an analysis and are entitled to ask questions."

The Trafalgar class submarine was alongside at Devonport after undergoing routine maintenance when the coolant, being pumped to an effluent tank on the jetty, spilled after a hose ruptured. The MoD said initial sampling had not detected any radioactive contamination in the local environment.