Lord Bristol died in his sleep and was found yesterday morning at his home, Little Horringer Hall in Suffolk.
The Marquess, who was 21 when he inherited Ickworth - a 4,000-acre estate near Bury St Edmunds - gave the property to the National Trust in April 1998 and moved into Little Horringer Hall, a five-bedroomed farmhouse on the estate.
In 1988 he was arrested in Jersey and later served nine months in prison after pounds 1,000-worth of cocaine was found aboard his private helicopter.
In December 1993 the Harrow-educated seventh Marquess, who once estimated his personal fortune at pounds 30m, was jailed for 10 months for possession of heroin and cocaine.
His agent, Simon Pott, said that he had been ill for a short time but his death had come as "a great shock". Mr Pott said he believed Lord Bristol had been suffering from a flu-type bug.Reuse content