Royal Navy sea graves are to be protected from looters by underwater drones, the First Sea Lord has said, as US forensics teams work to identify British remains of past conflicts.

Wrecks from Second World War battles in the Pacific have been raided in recent years by unethical scrap metal bounty hunters.

Admiral Sir Tony Radakin, the head of the Royal Navy, said there were “no easy answers” over the “very sensitive issue” of grave robbers disturbing Britain’s maritime war dead.

Speaking to the Telegraph in Hawaii, where he visited the Pearl Harbour memorial, Adm Radakin said although the graves are protected by law, “they’re not protected by physical presence everywhere”.

“My aspiration would be that in the future some of the technology that we’re seeing with our investment underwater…is that we’ll be using technology to cover either specific war graves, or to cover these large maritime protected areas.

“You supplement that with visits [by] drones.

“The way [we] will cover large tracts of the ocean will be a mixture of surface drones and underwater drones, both to meet your unique environmental responsibilities, your fishing responsibilities but also your specific responsibilities in terms of war graves.”

The British cruiser HMS Exeter goes down after heavy Japanese bombardment during the Battle of the Java Sea

Credit: Corbis

The wrecks of HMS Electra, HMS Exeter and HMS Encounter, sunk off the coast of Indonesia in the 1942 Battle of the Java Sea, were found to have been almost completely cleared five years ago.

Over 200 men died in the ships and the sites should have been protected as war graves.

Along with the Defence Secretary, Adm Radakin had earlier visited a US military forensic laboratory working to identify remains from past conflicts.

British Secretary of State for Defence Ben Wallace visits Hawaii where he toured the United States Indo-Pacific Command and Pearl Harbor

Credit: James Breeden

Ben Wallace with First Sea Lord Admiral Sir Antony Radakin in Hawaii

Credit: James Breeden

The team of scientists are working to identify the 81,700 US military personnel still unaccounted for, who fell in campaigns after the Second World War. Due to the nature of conflict, many bones the team of 700 finds belong to soldiers from other nations.

Dr Denise To, a forensic anthropologist and archaeologist, said she was confident her team would identify some of the 300 British soldiers still missing from the Korean War.

During the conflict in Korea, which raged from 1950 to 1953, 41 Commando of the Royal Marines was attached with US forces. They suffered significant losses.

The remains of some soldiers have been transported back to Dr To’s laboratory at Pearl Harbour for possible identification.

It is hoped the bones will turn out to be those of missing British soldiers, in which case they will be handed over to the MoD.

One way to help make an identification is by grinding down samples of bone and teeth to look for the relative levels of oxygen, carbon, nitrogen and lead in the isotopes. These levels are fixed in teeth by the age of 11.

Given the differences in the diets of British, American and Asian diets, Dr To is able to attribute the bodies to particular countries.

“You are what you eat,” she said.

All work in the laboratory is done ‘blind’ meaning different scientists are used for separate procedures to reduce bias.

“We have to take these measures to remain as objective as possible,” Dr To said, adding that she only had 31 reference DNA samples from the families of missing British personnel and no dental records at all.

Ben Wallace, the Defence Secretary said he would see if the MoD could assist in the laboratory’s work in any way.