Royal Navy's sonar testing may have killed dolphins off Cornish coast

The Royal Navy had been testing sonar equipment only miles from the bay where dozens of dolphins met an agonising death.

Another theory is that killer whales could be to blame for the shocking deaths of the dolphins.

The Ministry of Defence has admitted that a survey vessel was mapping the seabed 12 miles off the Cornish coast when the creatures swam to their deaths.

The admission will fuel suspicions that sonar caused the dolphins' sophisticated echo-location system to become scrambled, driving them to shallow waters where they suffered a slow and horrific death.