Sell-out Lloyd Webber show takes £10m but young singers don't get a penny

But the 50 youngsters in the choir in Andrew Lloyd Webber's new production of Joseph And The Amazing Technicolor Dreamcoat are not being paid a penny.

And now the actors' union Equity is launching an urgent investigation.

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The children spend about six hours a day travelling, rehearsing and performing, backing Lee Mead, who won the lead role of Joseph on the BBC1 talent show Any Dream Will Do. The show opened to critical acclaim last week and is reported to have made £10million in advance ticket sales.

According to Equity, the children, aged between seven and 13, should be paid a minimum of £190 a week each for their performances - half the adult minimum wage.

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But Joseph's producers - Lloyd Webber's Really Useful Group - make a payment to their theatre school and a donation to Children In Need - a decision that has angered many parents. The choir is drawn from the Carmel Thomas Youth Singers - a group run by music teacher Carmel Thomas, who has her own theatrical agency.

They are split into two groups and each child appears in no more than four shows a week to comply with employment law.

One father told The Mail on Sunday: "A lot of the mothers feel it's just great that their children are getting the opportunity to take part in the show.

"But most of the dads would say that the kids should get something. There's a lot of work involved.

"My daughter doesn't get back until about 11.30pm, so it's a very long day. It doesn't matter so much during the summer holidays but they've had to take time off school and it was quite difficult."

Equity spokesman Martin McGrath said: "We are beginning an investigation. It may be the show will argue that not paying the children is what they have always done and it is their practice - but we'd expect a big West End production to stick to the rules."

Joseph is consistently one of the most profitable musicals in theatre history and tickets at the 1,500-seat Adelphi Theatre in The Strand cost up to £60. The show is almost totally sold out for the first three months and 25-year-old Lee Mead's contract has been extended until June next year.

A Really Useful Group spokesman said a donation was being made to the Carmel Thomas Youth Singers to be spent on the youngsters. He added: "The children are not paid individually - they never have been in productions of Joseph.

"But if parents have a problem, why don't they pull the kids out if they feel like that?'

Carmel Thomas said that no parents had complained to her about pay. Asked if she was happy with the arrangement with the Really Useful Group, she said: "You need to speak to them. I can't comment."