Citing the source, the Los Angeles Times reported Monday that Rihanna, whose full name is Robyn Rihanna Fenty, is providing "ongoing" cooperation with detectives.
Brown, 19, was arrested Sunday night, booked on suspicion of making criminal threats, and released after posting $50,000 bail. He is being investigated for allegedly attacking Rihanna, his girlfriend, early Sunday morning, police said.
Rihanna reportedly suffered visible injuries in the alleged physical confrontation in a car the Times said was a Lamborghini rented by Brown. The alleged incident, following a Grammy Awards-related party, left Rihanna with bruises and a scratch to her face, police sources told the Times.
Both performers dropped out at the last minute from scheduled appearances on Sunday night's Grammy Awards telecast. Both were nominated for Grammys, but neither won an award.
The Wm. Wrigley Jr. Co. said Monday it is suspending its Doublemint gum ad campaign featuring Chris Brown.
"We have made the decision to suspend the current advertising featuring Brown and any related marketing communications until the matter is resolved," Wrigley said in a statement issued to TMZ Monday.
The celebrity Web site said Wrigley didn't indicate it was completely severing its ties to Brown just yet, however, as the company noted he should be "afforded the same due process as any citizen."
Brown's arraignment has been scheduled for March 5.
The Times said calls to Brown's lawyer, Mark Geragos, were not immediately returned.