Donny Osmond is 'devious, fraudulent and greedy', according to his former producer.
The one-time teen heartthrob and his sister Marie Osmond are being sued for millions of dollars by former producer Harold 'Chip' Lightman, who claims the pair reneged on an agreement to renew their contract with him this month.
Lightman believes he revived their careers with a Las Vegas production in 2008, and alleges both Donny and Marie cut him out of a contract which would have seen him continue on in his role.
The lawsuit states: 'Contrary to the wholesome, all-American, good-natured image that he presents to the public, defendant Donny's conduct ... has been anything but.
'He has conducted himself in a manner that is underhanded, devious, fraudulent and greedy. The clear goal of his actions has to line his own pockets with ill-gotten gains to fund his lavish lifestyle of exotic cars, luxury hotel suites and private jets - all off the backs and hard work of those who worked tirelessly to support his career.'
He also hit out at Marie claiming she is nothing like the public persona she likes to present.
It added: 'Despite Marie's seemingly innocent nature, she too is liable for the fraud perpetuated by Donny through her acquiescence, awareness and utter failure to disclose ... the steps taken by Donny to deceive and circumvent their contractual obligations.'
Lightman also claims he was ordered to take a 50 per cent pay cut to continue working with the pair on the 'Donny and Marie Show' at the Flamingo Hotel.
He also attacked the Osmonds on his twitter page, claiming he has been approached 'for a 'tell all' book' on the singing siblings.
Donny, 52, and Marie, 50, have made around £1 million a year as well as 40 per cent of the gross box office receipts from their Las Vegas show since April 2008.