Authorities on Friday raided a private golf tournament in Norco at which prostitutes allegedly were selling their services on the fairways.
More than 100 people were detained for questioning by Riverside County sheriff's deputies after undercover investigators saw sex taking place at the Hidden Valley Golf Club, authorities said.
Among the detainees were 10 to 15 women, as well as employees and golfers, said sheriff's spokeswoman Shelley Kennedy-Smith.
By 9 p.m., half of those detained had been released.
No arrests had yet been made, but more than 40 people were still being questioned, Smith said.
Investigators said they believe golfers had sex with prostitutes at the club at least once before. Authorities have been watching Hidden Valley for about three weeks, they said.
On Friday, the club was reserved for a private tournament and several tents were pitched on the course. Smith said investigators observed sex between golfers and women in plain sight on the fairways.
