Image copyright Thames Valley Police Image caption A woman believed to be missing Ashleigh Fair was seen on CCTV in Marble Arch, London

A missing former Royal Ballet School pupil who walked out of a hospital and into a blizzard wearing no shoes may have been spotted on CCTV, police say.

Ashleigh Fair, 19, was last seen leaving the Royal Berkshire Hospital in Reading at 09:30 GMT on Thursday.

CCTV footage from shortly after 11:30 on the same day shows a woman, believed to be Ms Fair, in London's Marble Arch.

Thames Valley Police described Ms Fair as seriously ill and said officers were increasingly concerned for her welfare.

Ms Fair, who requires "urgent medical assistance", was not wearing shoes when she walked out into the freezing conditions.

It is believed after leaving the hospital she took a taxi to Cumberland Place in Marble Arch.

Image copyright Thames Valley Police Image caption Ashleigh Fair walked out of hospital without shoes on

She was wearing a green and pink knitted jumper, black tracksuit bottoms and pink socks.

Det Sgt Sarah Roxburgh said: "Ashleigh is not dressed appropriately for the extremely cold weather we have been experiencing and was not wearing any shoes at the time she went missing."

Appealing directly to Ms Fair, she added: "If you see this appeal, please contact police urgently. We need to check you are safe."