LONDON (AFP) –- U.S. magician David Blaine was on Sunday ending his fast inside a glass box suspended above London's River Thames after 44 days of intense public scrutiny, intermittent ridicule and -- experts warn -- possibly permanent damage to his health.

The small transparent container next to Tower Bridge was expected to be lowered to the ground some time after 09:00 P.M. (2000 GMT) in front of a crowd, organizers of the stunt predicted, of around 250,000 people.

The 30-year-old illusionist was then due to be placed on a stretcher and rushed to a private hospital, where a medical team will assess whether 44 days of drinking only water has permanently affected his heart or other organs.

Blaine, who has suffered severe palpitations and breathing difficulties in recent days, is expected to stay in hospital for some days, and will not be restored to full health for around six months, doctors say.

A nutritional expert tasked with preparing a briefing on restoring Blaine to health warned Sunday that the U.S. entertainer could even die through "re-feeding syndrome" if he ate too fast.

While treating the health problems Blaine had encountered during his fast, caution was needed "because inappropriate feeding can precipitate serious problems including sudden death," Professor Marinos Elia said.

Elia also dismissed suggestions that Blaine had kept himself alive by having dissolved nutrients such as glucose added to his water supply, saying that the water was pure.

Since Blaine began the stunt on September 5, the area around his glass cell has become one of London's most unusual tourist sights, attracting both admiration and contempt.

Critics have condemned the fast -- officially titled "Above the Below" -- as both pointless and offensive given that many millions of people go hungry around the world each day without being paid handsomely for it, unlike Blaine.

Some have come up with increasingly inventive ways to taunt or unsettle Blaine such as using a remote-control model helicopter to dangle a cheeseburger in front of the starving magician.

Others drove golf balls off Tower Bridge, threw eggs, used a homemade catapult to shoot paint bombs at the box, banged drums to keep him awake at night or merely shouted abuse.

The antics prompted a debate in British newspapers as to why Blaine had not received the same reverent appreciation seen during earlier stunts in the United States, such as encasing himself in ice for 61 hours and standing on top of a tall pole for a day-and-a-half.

In general, the verdict has been that while some of the anti-Blaine antics were excessive, the public response is a fine example of British people's antipathy to pretension and pomposity.