An investigation will continue into what caused a Royal Navy helicopter to ditch in the Channel during a night-flying exercise, resulting in the death of a member of Navy personnel.

There were three crew members on board at the time of the incident and two of them were rescued and taken to hospital, the Ministry of Defence said.

The Merlin helicopter crashed off the coast of Dorset on Wednesday night during the training exercise with the HMS Queen Elizabeth aircraft carrier, according to the Royal Navy.

The family of the deceased, who has not been named, have been informed.

Prime Minister Sir Keir Starmer, posting a message on X, said: “Deeply saddened to hear of the tragic death of a member of the Royal Navy.

“My thoughts are with the family and loved ones during this painful time.”

Defence Secretary John Healey described the news as “dreadful”.

He told the PA news agency while on a visit to HMS Diamond in Portsmouth: “Dreadful news. Truly dreadful news.

“I use dreadful because this is what everyone connected to the armed forces (dreads), news of personnel in service dying.

“All my thoughts and the thoughts of those in the wider Navy I’ve been with today are with the family, the friends and the close colleagues of the one we’ve lost today.”

In a statement, the Royal Navy said: “It is with great sadness that we must report a member of the Royal Navy has died following a training incident last night.

“Our thoughts are with the family – who have been informed – and all those affected at this sad time. A full investigation will take place.

“The incident involved a Merlin Mk4 helicopter in the English Channel near Dorset that ditched while conducting night-flying exercises with HMS Queen Elizabeth. There were no other fatalities or serious injuries.”

David Learmount, an expert on aviation issues, called the Merlin Mk4 a “sophisticated” helicopter which is “pretty resilient”, saying it was “very unusual” for such an incident to happen.

On the investigation into the cause of the incident, he told PA: “If there was a technical aspect to this they are going to check all the other helicopters that are like this one to make sure it’s not going to happen to them too.

“If they have a reason to do so they will say we’d better ground all the others until we know the reason why it happened.”

The Merlin Mk4 helicopter is used by the Royal Marines and has been deployed globally to provide disaster relief.

It is considered the “world’s most advanced amphibious battlefield helicopter” and can carry up to 24 troops, according to the Royal Navy.

HMS Queen Elizabeth is described on the Navy’s website as “the largest and most powerful vessel ever constructed for the Royal Navy”, which is capable of carrying up to 40 aircraft.

The vessel is the Navy’s Fleet Flagship and can carry senior naval staff, receive foreign dignitaries and act as a command and control centre for the Royal Navy.