The five brothers Alan, Wayne, Merrill, Jay and Donny were known as The Osmond Brothers.
Donny performed with his brothers on stage and on tv for several years before he recorded an album.
"Despite Marie's seemingly innocent nature, she too is liable for the fraud," he alleges.
Mr Lightman has also taken his attack on Osmond to Twitter, where he told his followers – which include 10 Downing Street – that he "has already been approached for a 'tell all' book".
“The book’s topic is the mental illness of depression and how it can shatter families, but Marie plans to reveal everything about her life struggles, including a lot of things her family does not want exposed.” Marie has overcome her terrible battle with depression and has since become one of the most popular women in the entertainment industry.
She has a talk show on the Hallmark Channel, regular sold-out Las Vegas performances at the Flamingo hotel, a new line of dolls sold on QVC, books written by her, handcrafting and her philanthropic work with Children’s Miracle Network.