Michael Crawford has played his role wearing a fat suit

The 63-year-old star is suffering from an "acute flu virus" and has been ordered not to return to the stage until he has made a full recovery.

Ball, who has previously starred in Les Miserables and Phantom of the Opera, will play the role of Count Fosco.

The 42-year-old had previously planned to join the musical in late February.

Crawford, who has also starred on stage in The Phantom of the Opera and Barnum, still plans to reprise his role in the Andrew Lloyd Webber in early April.

The musical, which is based on Wilkie Collins' 1860 novel, opened in September and was recently nominated for five Oliver Awards, including best musical.

Singer Ball, who also represented the United Kingdom in the 1992 Eurovision Song Contest, said it was an "enormous challenge" to step into the shoes of Crawford.