LONDON (Reuters) -

Harry Potter star 

Daniel Radcliffe

will strip

off for his London stage debut as a psychologically disturbed stable boy in "Equus."

The 17-year-old, currently making the fifth Harry Potter film, will star alongside Richard Griffiths, who plays his grumpy uncle in the wizard sagas.

Radcliffe will play Alan Strang, a stable boy who is interviewed by a psychiatrist after he blinds six horses with a metal spike. In Peter Shaffer's controversial play, the role requires the actor

to ride

naked on

his horse.

"This is an extraordinary play and, yes, there is a

scene of nudity

in it, but that's not what the play is about," said Radcliffe's publicist Vanessa Davies.

"He finishes shooting 'Harry Potter and the Order of the Phoenix' in October or November and rehearsals are starting in January," she added. The play is expected to open in March.

Harry Potter and the Order of the Phoenix is the fifth  J.K. Rowling book to be turned into a film. There are doubts about

whether Radcliffe can

continue to play the

boy wizard until

the end of the series.

Rowling is now writing the seventh and final book of the hugely successful series.

The first four Harry Potter films have amassed around $3.5 billion worldwide at the box office.