Comedian Peter Sellers, posing in 1974 as Inspector Clouseau in The Pink Panther Returns, died of a heart attack in July 1980. ((Evening Standard/Getty))

A letter signed by the late Peter Sellers, and believed to be the last time he put his signature to anything, indicates he was trying to prevent the bulk of his fortune from being handed to his fourth wife, Lynne Frederick.

The letter, dated July 22, 1980, was created the very day the Pink Panther actor collapsed from a massive heart attack at the Dorchester Hotel in London.  The comic never regained consciousness after lapsing into a coma.

The 54-year-old performer was due to undergo major heart surgery in Los Angeles at the time of his collapse. He spent two days in a London hospital and died on July 24.

At the time, Sellers was separated from his fourth wife and had been trying to reconcile with his three children, Michael, Sarah and Victoria, from whom he'd been estranged.

The letter states that: "The Trustees shall hold, manage, invest, reinvest the trust property for the benefit of Victoria Sellers, daughter of the Grantor, born January 20, 1965 upon the following terms".

It also says that Victoria, his daughter with second wife Britt Ekland, should inherit £20,000 ($32,365 Cdn) when she turns 21.

In the end, Frederick inherited most of the actor's fortune, about £5 million ($8.1 million Cdn), while his three children got only £800 ($1,295 Cdn) each.

After Sellers married actress Frederick in 1977, he altered his will. The pair separated three years later. Frederick died in 1994. 

Victoria is now a jewelry designer in Los Angeles while Sarah runs an antique shop in London. Michael died of heart failure in 2006 at age 52.

The letter is being put up for sale over the weekend — along with a Golden Globe award Sellers won for his role in the 1979 comedy Being There  — by British auctioneers Henry Aldridge and Son.

The letter had been in the hands of a private collector.