Answer:
Warwick Castle remained the property of the Greville family until 1978 when David Greville, Lord Brooke sold the castle to the tussauds group for 1.5 million pounds. Lord Brooke had been in possession of the Castle and it's Estates since 1967 when his father the 7th Earl transferred ownership in order to avoid death duties. Only in 1984 did David Lord Brooke inherited the Earldom on the death of his father. David the 8th Earl of Warwick died in 1996 and his son Guy inherited the title and became the 10th Greville Earl of Warwick. He lives in Western Australia and has no links to his former ancestral home.