J. Paul Getty III, who was a grandson of the oil baron once believed to be the richest man in the world and who achieved tragic notoriety in 1973 when he was kidnapped by Italian gangsters, died Saturday at his home near London. He was 54.

His son, the actor Balthazar Getty, confirmed the death in a statement relayed in an e-mail from Laura Hozempa, one of his agents. Mr. Getty had been wheelchair-bound since 1981, when a drug overdose caused him to have a stroke that left him severely paralyzed, unable to speak and partly blind.

At the time of his abduction, Mr. Getty was just 16 and living on his own in Rome, where his father, J. Paul Getty II, had, for a time, helped oversee the family’s Italian business interests.

Expelled from a private school, the young Mr. Getty was living a bohemian life, frequenting nightclubs, taking part in left-wing demonstrations and reportedly earning a living making jewelry, selling paintings and acting as an extra in movies. He disappeared on July 10, 1973, and two days later his mother, Gail Harris, received a ransom request. No longer married, she said she had little money.