This is the view theatregoers will get tonight of Harry Potter star Daniel Radcliffe.

And the question some are asking is: will he end up wishing he had brought along Harry's cloak of invisibility?

It won't be for reasons of modesty - Radcliffe, 17, has shown himself to be remarkably relaxed about exposing his naked body to the world - but there are those who wonder whether this full-on display, in the West End revival of Peter Schaffer's play Equus, could prove ultimately damaging to the teenage star's career.

Already extremely famous for doing one thing - playing a boy wizard - there is a danger, they argue, that he could end up being known for doing one other thing - getting his kit off.

In the play, enjoying its first major revival since it was first staged more than 30 years ago, Radcliffe plays stablehand Alan Strang, who blinds six horses with a metal spike after a disturbing sexual experience.

Executives at Warner Bros, the studio behind the film versions of J K Rowling's books, are said to have been "utterly dismayed" by publicity shots of Radcliffe naked, as well as the fact that he spends a full 10 minutes on stage without his clothes.

He will not be the only performer in the nude: there is also Joanna Christie, 24, who plays the stablegirl with whom he has a relationship.

Studio chiefs are said to fear the scenes could damage their multi-million-dollar film franchise and could even lead to Radcliffe being replaced as the young wizard.

One was quoted as saying: "Warner Bros have been building up their publicity machine for Harry's first - chaste - screen kiss when the next Potter film (Harry Potter And The Order Of The Phoenix) comes out in the summer.

"Now our star is out there doing full-frontal sex. We've been blown completely out of the water by this."

Equus has its preview tonight at the Gielgud Theatre. The play opens on 27 February.