Peter Sellers had reached a final divorce settlement with his fourth wife that would have deprived her of any claim on his estate — but he died before the document became binding, according to legal papers that have come to light.

The settlement, which was never made public, meant that Lynne Frederick was expecting to walk away from the three-year marriage to one of the world’s best-loved comic actors with £375,000 in a one-off payment and ownership of their Los Angeles home.

In the event, Sellers died at 54 on July 24, 1980, before the divorce became final, and Ms Frederick was able to claim his entire £4.5 million estate. His three children, from previous marriages, were left £750 each.

Ms Frederick died an alcoholic in 1994 and the fortune left by the star of the Goons and Pink Panther films has since been inherited by her daughter by her next-but-one husband after Sellers. Cassie Ungar, 25, who lives in Los Angeles, never met her benefactor.

Times Archive, 1985: $1m damages awarded to Peter Sellers' widow

Lynne Frederick was awarded damages at the High Court over the making of the film The Trail of the Pink Panther

• Peter Sellers loses his fight for life, 1980

• Last tributes paid to Peter Sellers

Related Links

• Lost Sellers films on screen after 50-years

• Cover story: True Peter

Rumours that Sellers planned to cut his estranged wife out of his will began circulating after his death but Ms Frederick always denied them. Both parties signed the agreement after they separated but, as the decree absolute was never completed, they were legally still married when he died.

The fortune inherited by Ms Frederick included properties around the world, Sellers’s art collection, family heirlooms and the rights to his films.

His children, Michael, Sarah and Victoria, were unable to challenge the will as they had been given token amounts and had not been left out “by mistake”.

The agreement, dated June 15, 1979, was acquired by a collector and is being sold at auction in Devizes, Wiltshire, on November 14.

Roger Lewis, the author of The Life and Death of Peter Sellers, said that Ms Frederick publicly denied knowledge of the settlement. He said Sellers had been in the process of rewriting his will to leave the bulk of his fortune to the British Heart Foundation but collapsed after a heart attack and died the day before he was due to sign it.

Mr Lewis was told by Spike Milligan, another former member of the Goons, that he had pleaded with Ms Frederick, a successful actress, to make provision for Sellers’s children. “She relished the role of Mrs Sellers and played the grieving widow after he died, which his children found deeply offensive,” Mr Lewis said. “His first wife, Anne, and Spike Milligan went to see Lynne Frederick at the Dorchester Hotel and implored her to make some sort of settlement towards the children. She said no, because it was his last wish for her to have his money. But on the basis of this document it would seem that she shouldn’t have claimed his £4 million estate or the royalties to his films.”

He claims that Ms Frederick had coerced Sellers into cutting his ties with his children before they married in 1977. “When she came along he was in his fifties and she was 30 years younger than him. She was very manipulative. She didn’t want him to have anything to do with his former relationships, including his children. She threatened to leave him and his way of keeping her was to write his will so that she inherited the lot. I never met anyone who had a good word to say about her. She was a nasty, manipulative little gold-digger.”

The auctioneer, Andrew Aldridge, who expects the document to sell for up to £3,000, said: “Peter Sellers’s friends said he had been trying to cut Lynne out of his will and these papers substantiate those claims.”

Of Sellers’s children, Michael died of heart failure in 2006 at 52, Victoria, from his second marriage, to Britt Ekland, is a former drug addict living in California; and Sarah runs an antique teddy bear shop in London.

Times recommends

• A vicar’s wife: ‘There is no one to fight for us’
• Mutton dressed as lad: I’ve seen the future
• Think yourself slim with our hypnodiet podcast