It appears that Mossad agents killed Maxwell on his yacht somewhere in the sea around the Canary Islands (location of the site here is not precise and needs to be updated).

Robert Maxwell

Ian Robert Maxwell MC (10 June 1923 – 5 November 1991) was a Czechoslovakian-born British media proprietor and Member of Parliament (MP). He rose from poverty to build an extensive publishing empire. His death revealed huge discrepancies in his companies' finances, including the Mirror Group pension fund, which Maxwell had fraudulently misappropriated.

• http://en.wikipedia.org/wiki/Robert Maxwell
• Page 209-210 -Thomas, G., 1995, 2007, Gideon’s Spies: The secret history of the Mossad: Thomas Dunne Books, New York, 616p.