The daughter of the couple who created Thunderbirds is threatening legal action against ITV over millions of pounds in lost royalties.
Dee Anderson claims her stepfather Gerry Anderson woefully undervalued the hugely-popular puppet series when he sold the TV rights in 1962.
Speaking exclusively to MailOnline Dee, 68, says the deal made the TV company 'millions of pounds', but left her family, including her mother and co-creator Sylvia, seriously out of pocket.
Dee said: 'I want retrospective action over the deal. ITV made millions of pounds from something my mother helped create but she's received barely anything.
'She was kept out of any negotiations purely because she was female and never got the recognition she deserved.'
Sylvia Anderson and her husband Gerry Anderson were the original creators of Thunderbirds
Gerry (pictured in 2005) died in 2012 aged 83. He sold the TV rights to Thunderbirds in 1962 for £110,000. His stepdaughter Dee Anderson, 68, claims he woefully undervalued it
Dee's mother Sylvia Anderson, who produced the series and was the voice of Lady Penelope, was cut out of the deal before her acrimonious divorce from Gerry, according to Dee
The classic British series centred around the missions of the International Rescue team who were based on the fictional Tracey Island, where they kept their fleet of Thunderbird machines
Gerry and Sylvia Anderson turned Thunderbirds into a global phenomenon which spawned spin-offs including Captain Scarlet.
The classic British series centred around the missions of the International Rescue team who were based on the fictional Tracey Island, where they kept their fleet of Thunderbird machines.
Sylvia, who voiced the show's legendary character Lady Penelope, was the creative force, while Gerry was known for his technical brilliance and also looked after the business side.
Despite Thunderbirds' huge popularity, Gerry sold the rights to ATV, which later became ITV, in 1962 for a paltry £110,000, despite receiving bigger and more lucrative offers elsewhere.
Dee Anderson is fighting ITV over the deal to sell the Thunderbirds' TV rights in 1962
He later sold the rest of their production firm AP Films to British production company ITC and ATV for just under £15,000 in 1975 - shortly after his bitter split from Sylvia, without her consent.
The former couple finalised their divorce in 1981 and while Sylvia spent the rest of her life struggling with money, even remortgaging her house in Bray, Berks, Gerry lived comfortably in his Oxfordshire cottage with third wife.
She also claims Sylvia was not credited on any further Thunderbirds-related material in a bid to 'airbrush' her from the show's history.
In her complaint, Dee's lawyer told MailOnline that they want the deals investigated because, they say, Gerry didn't have the