Rihanna and Chris Brown

The shocking news of Chris Brown's abrupt Grammy cancelation and arrest in a felony battery case had the industry buzzing Monday about whether his girlfriend Rihanna, also a Grammy no-show, was involved. Police refuse to identify Brown's accuser and no charges have been filed against the 19-year-old singer, who was booked on criminal threats and released on $50,000 bail on Sunday night.

"LAPD arrested him, but we have not filed any charges because they have not given us any evidence yet," Los Angeles District Attorney's Office spokeswoman Jane Robison told TVGuide.com. Brown is due in court March 5.

Brown, who's been dating Rihanna for over a year, surrendered to police Sunday night.

The Los Angeles Times has identified Rihanna as the accuser, but the 20-year-old singer's rep declined to confirm reports, telling TVGuide.com: "Rihanna is well. Thanks for your concern and support."

TVGuide.com's calls to Brown's attorney, Mark Geragos, have not been returned. Geragos represented Winona Ryder during her 2001 shoplifting arrest, Michael Jackson during his child molestation trial and convicted murderer Scott Peterson.

The case stems from an early Sunday incident shortly after Brown and Rihanna left Clive Davis' pre-Grammy party, where they were reportedly in good spirits. Police said they responded to a call in which an unidentified woman claimed she got into an argument with the singer and he attacked her. The woman had visible injuries on her, police said. Brown had left the scene when officers arrived.

Later Sunday, Grammy officials announced that Brown and Rihanna pulled out of their performances, leaving the show scrambling to fill their vacant slots. Double-nominee Brown was to perform "Forever," while Rihanna, also a nominee, was scheduled to sing "Live Your Life/Disturbia." Brown's performance was replaced by Justin Timberlake, Al Green, Boyz II Men and Keith Urban, who came together to perform Green's "Let's Stay Together." The switch was not mentioned on the broadcast.

Following Sunday's performance switch-ups, one of Brown's endorsement deals was put on hold. Wrigley said Monday that it is suspending its current ad campaign with the star until the allegations against him and the potential legal case are resolved, according to a statement. The company expresses concern over the "serious allegations made against Chris Brown," but said the singer should be "afforded the same due process as any citizen."

Wrigley asserted that any additional comments would be "premature" due to the "speculative" nature of the incident.