The Young Ones star died in June last year (14), aged 56, and probate records show he did not leave a valid will for his $1.9 million (£1.2 million) estate.

The move means his widow Barbara, who was married to Mayall for 29 years, and their three adult children, Rosie, Sidney and Bonnie, now face a lengthy legal process and a potentially hefty inheritance tax bill.

Barbara tells Britain's The Times newspaper, "I haven't heard anything from my lawyers yet."