Sinn Fein president Gerry Adams expressed his shock and sadness at the news.
"Gerry and his father Giuseppe were two of the most infamous examples of miscarriages of justice by the British political and judicial system," Mr Adams said.
"Their story was told graphically in the film In The Name Of The Father.
"To his family and friends I want to extend my sincere condolences."
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Mr Blavatnik, whose empire includes the Warner Music Group, has an estimated fortune of £13.17bn according to the Sunday Times Rich List.
Find out what to expect from the weather if you are running in the big race in London or watching from the sidelines.
It will be a soggy start to the weekend and temperatures will drop making it feel colder than in recent days.