Israeli agents used poisoned chocolate to assassinate a senior Palestinian terrorist in the 1970s, according to a new book.

"Striking Back," an expose of Mossad reprisals by Israeli intelligence veteran Aaron Klein, contains a chapter about the killing of Wadi Haddad, chief of the Popular Front for the Liberation of Palestine.

Wanted for masterminding several airline hijackings, Haddad took refuge in Iraq in 1976.

But Mossad intelligence agents, using a Palestinian turncoat, managed to slip him Belgian chocolates coated in a slow-acting poison that killed him over the course of a few months, Klein claims.