Illusionist David Blaine is to receive underwater medical treatment after doctors in the US expressed concerns for his health.

The magician, who is spending a week submerged in a "human aquarium" in The Lincoln Centre, New York, has peeling skin and pain like "constant pins and needles".

But Blaine's spokesman Pat Smith is adamant that the star is determined to complete the challenge that he has set for himself.

Mr. Smith said, "Doctors are concerned that he's weakening. They are going to work with him through the weekend, trying to stabilise both his diet and his training regime."

At the end of the challenge, Blaine will attempt to beat the world record for holding breath, which currently stands at 8 minutes and 58 seconds.