MALIBU, Calif. — Authorities have accused Oscar-nominated actor Ryan O’Neal of assaulting his adult son at the actor’s home over the weekend.

Deputies and paramedics were called to the older Mr. O’Neal’s home at 12:30 a.m. Saturday “regarding a battery that had occurred,” Los Angeles County Sheriff’s Lieutenant John Benedict said yesterday.

“Deputies determined … Griffin O’Neal, his son, had been assaulted by his father,” Lieutenant Benedict said.

Ryan O’Neal, 65, was arrested and accused of assault with a deadly weapon and negligent discharge of a firearm. He was released on a $50,000 bond.

The older Mr. O’Neal does not have a listed telephone number, and no other contact information was immediately available.

Lieutenant Benedict could provide no details on what caused the dispute. No one was treated for injuries.

The twice-divorced Ryan O’Neal, known for his boyish good looks, went from a TV soap opera to an Oscar-nominated role in “Love Story.” He also appeared in films including “Paper Moon,” “Barry Lyndon,” “Green Ice,” and “Zero Effect.”

Mr. O’Neal had two children with his first wife, Joanna Moore: actor Griffin O’Neal and actress Tatum O’Neal, his co-star in the 1973 movie “Paper Moon,” for which she won an Oscar for best supporting actress. He was romantically involved with Farrah Fawcett for years; they never married but had one son, Redmond.

Griffin O’Neal was given an 18-day jail sentence for not performing 400 hours of community service ordered by the judge who found him guilty of reckless boating in the 1986 accident that killed the son of director Francis Ford Coppola, Gian-Carlo Coppola.

Griffin O’Neal also pleaded no contest to a drunken driving charge in 1989 and was sentenced to probation. In 1992, he pleaded no contest to charges that he shot at his estranged girlfriend’s unoccupied car. At the time, he agreed to spend a year in a live-in drug rehabilitation program and serve five years on probation.