The female casualty had been walking on the beach at the Lizard in Cornwall when she was caught by a freak wave that swept her into the water and out to sea.

The lifeboat and coastguards were all scrambled to her aid just after 1.15pm on Monday.

They carried out a land and sea search of the area following reports of a person being in the water.

The woman, believed to have been on holiday in the area, was subsequently found on the beach and was winched into the coastguard helicopter, which transferred her to the Royal Cornwall Hospital in Truro.

However, a coastguard spokesperson confirmed this morning that having been airlifted to Treliske, she was declared dead at the hospital.

A Lizard lifeboat spokesperson described the conditions as "treacherous" and said the volunteer crew's thoughts were with all involved.

A spokesman from Porthoustock Coastguard Rescue Team said the team initially received information that there could be two or possibly three people in the water.

He added: "Just as we arrived on scene it was confirmed that this was not the case and the extra persons who had attempted a rescue were accounted for.

"On arrival at the scene Mullion Coastguard Rescue Teams had already pulled the casualty from the water and we performed CPR on her along with paramedics."

He added: "Shortly afterwards, the casualty was winched into the helicopter and conveyed to Treliske. Our thoughts are with the family and friends at this time."