Associated Press
Actor Ryan O'Neal is shown in an arrest photo on Wednesday.

Ryan O'Neal and his son were arrested Wednesday morning after authorities said they found drugs at the actor's home in Malibu, Calif., during a routine check associated with Redmond O'Neal's probation.

Investigators suspect both men had methamphetamine, but the substances still need to be tested, Los Angeles County Sheriff's spokesman Steve Whitmore said.

Los Angeles Sheriff's deputies and probation officers went to O'Neal's home for a routine check of Redmond O'Neal, who is serving three years of probation after pleading guilty in June to drug possession charges.