Lady Lucan, whose husband famously vanished more than four decades ago, has been found dead at her home in London.
Police forced entry to the 80-year-old's home in Westminster yesterday afternoon after she was reported missing, and found her unresponsive.
A Metropolitan Police spokesman said: "Police attended an address on Eaton Row in Westminster ... following concerns for the welfare of an elderly occupant."
"Officers forced entry and found an 80-year-old woman unresponsive. Police and London Ambulance Service attended. Although we await formal identification we are confident that the deceased is Lady Lucan."
Police say her death is being treated as unexplained but is not believed to be suspicious.
Her son George Bingham, the 8th Earl Lucan, said: "She passed away yesterday at home, alone and apparently peacefully.
"Police were alerted by a companion to a three-day absence and made entry today."
Lady Lucan was one of the last people to see her husband John Bingham, the 7th Earl of Lucan, alive before he disappeared.
Lord Lucan's family once owned over 60,000 acres in Co Mayo and lived on the outskirts of Castlebar.
He vanished after the murdered body of Sandra Rivett, nanny to his three children, was found at the family home at Lower Belgrave Street, central London, on 7 November 1974.
Even though he was officially declared dead by the High Court in 1999, Lord Lucan has reportedly been sighted in Australia, Ireland, South Africa and New Zealand, and there are even claims that he fled to India and lived life as a hippy called "Jungly Barry".
The same night as his disappearance, the attacker also turned on Lady Lucan, beating her severely before she managed to escape and raise the alarm at a nearby pub, the Plumbers Arms.
Lucan's car was later found abandoned and soaked in blood in Newhaven, East Sussex, and an inquest jury declared the wealthy peer the killer a year later.
Last year, a British judge officially declared Lord Lucan dead, nearly 42 years after he disappeared.
His only son, Lord George Bingham - now the 8th Earl of Lucan - applied for a declaration under the Presumption Of Death Act, which came into effect in 2014, so he could inherit the title.
