Blaine faces lasting damage

David Blaine could be just a week away from permanently damaging his body by continuing his high-profile endurance stunt.

The US illusionist is half-way through his challenge of going without food for 44 days in a Perspex box near Tower Bridge.

Dr John Potter, an expert on solitary confinement, said: 'David is showing signs of withdrawal and this will increase as he focuses more on the internal world and leaves the external world behind.'

Unusual weather and relentless disturbances have taken their toll - with the heat making him lose salt and feel unstable. Urine tests over the weekend appeared to show Blaine is not cheating by taking supplements with his water.

The time the 30-year-old New Yorker spends standing up has reduced to just ten minutes a day and he is reporting dizziness and instability when he stands.

He also has a sweet taste in his mouth like pear drops, which is caused by ketones - a by-product of fat reserves breaking down.

Blaine's publicists insist he was given a thorough medical before starting the challenge and his body will be able to cope.