A brilliant young scientist has died after being attacked by a seal in the seas off Antarctica.

Marine biologist Kirsty Brown, 28, from Horsham, is believed to have drowned after being pulled underwater by a powerful leopard seal while snorkelling off the Rothera research station.

Kirsty, who had been at the research base on the Antarctic Peninsula for a year as part of the British Antarctic Survey (BAS), was attacked without warning as she swam with a colleague in a bay near the base at about 4.50pm local time (8.50pm UK time) on Tuesday.

The two-man shore team raised the alarm and a rescue boat was launched in an attempt to save her.

Colleagues pulled her from the icy water and transferred her to the station where a doctor battled to restart her heart for an hour.

Kirsty's family, who live in Marlpost Road, Southwater, were last night coming to terms with her death.

Her retired parents, Tim and Judith, sisters Didi and Camilla and brother Duncan issued a joint statement saying: "Naturally, we are devastated about the news from Antarctica - it all seems quite unreal.

"Kirsty was a great girl and we are all very proud of her. Right now we are looking to spend some quiet time at home with the family."

BAS director Professor Chris Rapley said: "This is tragic and shocking. Kirsty was a vibrant, dynamic individual, committed to her science and with a promising scientific career ahead of her.

"The Rothera team reacted in a highly efficient and professional manner of which we, and they, can be proud.

"They are, however, shaken by the loss of a colleague and will need our support."

Kirsty joined the BAS on a 30-month contract last summer.

She was a qualified and experienced scientific diver who carried out research at Adelaide University in Australia after graduating in geology from Royal Holloway College in London and completing an MSc in oceonography at Southampton University.

Her work in the Antarctic was a study on the impact of iceberg scouring on near-shore marine animal communities.

An inquest will be held.

Leopard seals can be up to 10ft long and weigh as much as 70 stone.