In 1980 Channel 10 promoted the ''Who shot J.R?'' episode of Dallas turning it into a TV event, but in the end throat cancer took his life in a Dallas hospital.

The son of actress Mary Martin and a district attorney, Benjamin Jack Hagman, he first shot to fame playing astronaut and genie keeper Major Anthony ''Tony'' Nelson in the 1960s sitcom I Dream of Jeannie alongside Barbara Eden. But it was as J.R. Ewing in Dallas that he became a household name and Hagman was joined at his bedside by co-stars Linda Gray and Patrick Duffy, who played his wife Sue Ellen and brother Bobby, a United Kingdom newspaper has reported. Linda Gray's agent, Jeffrey Lane, confirmed the death, The Dallas Morning News said.

Hagman battled drugs and alcohol for years and had a liver transplant in 1995 and would reportedly drink bottles of champagne on the Dallas set.

While networks across the world promoted the 1980 season of Dallas with the teaser of ''Who shot J.R?'', Hagman himself performed a deft pay-bargaining move. Hagman disappeared to London for a family holiday delaying signing his new contract while the producers agonised over whether his character would die or not.

Holding out for a higher salary paid off and Hagman became one of the highest paid television stars of the day.
Hagman was the only actor to appear in all 356 episodes of Dallas.

Hagman was nominated twice for the Outstanding Lead Actor in a Drama Series Emmy Award in 1980 and 1981, but failed to gain the gong. He was also nominated for four Golden Globes.

In October, last year, he announced he had ''treatable'' throat cancer and would undergo treatment while he filmed the reprised Dallas.

At the time he was reported to have said: ''As J.R. I could get away with anything – bribery, blackmail and adultery. But I got caught by cancer. I do want everyone to know that it is a very common and treatable form of cancer.''

The rebooted Dallas began on Channel 9 in August.

He married Maj Axelsson in 1954 and the couple had two children and made efforts to ensure his children knew him, something he missed with his own actress mother.

When the family lived in Malibu he became the centre of the social set there and often led processions down the beach while dressed in costume. He garnered the nickname ''The Mad Monk of Malibu'' for wearing a purple gorilla suit, a train engineer's costume and a long hooded black robe.

Hagman's official website was jammed on Saturday as fans heard of his death.