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*Read the latest updates on the Brown investigation here
UPDATED: R&B's golden couple, Chris Brown and Rihanna, is embroiled in a domestic drama that has taken the gossip mills by storm.
The pair was slated to be the star attraction at the Grammys - both were scheduled to perform at the glitzy music awards event in Los Angeles on Sunday (last night NZ time) - but things went horribly awry when Brown was detained by police in a felony battery investigation for allegedly roughing up Rihanna.
Several news reports say that Brown, 19, turned himself in to the LAPD on Sunday at around 6.30 pm (local time). He was then booked on suspicion of making criminal threats - charges that could lead to a maximum of four years in jail - posted US$50,000 bail and later released.
"He was very professional and didn't appear to have injuries," police told E! adding, "He's a good looking young man."
Brown is also being investigated for alleged domestic violence and felony battery, the LAPD said. More charges could also be filed later, sources say.
Brown is now due in court on March 5.
The alleged assault occurred on Sunday near Hancock Park in Los Angeles.
Police say an unidentified woman, dialled 911 and claimed she'd been attacked by Brown after getting into a fight with him.
According to a police statement, Brown and the woman were in a vehicle around 12.30am on Sunday, when, according to the victim, they became involved in an argument.
After stopping his car, Brown and the woman got out and the argument continued.
When police arrived, the woman, reportedly with visible injuries to her face, named Brown as her attacker, but he'd already left the scene.
"After stopping his car, Brown and the woman got out and the argument escalated," a spokesperson for the Los Angeles police Department told The Sun.
"The woman suffered visible injuries and identified Brown as her attacker."
Rihanna subsequently yanked her scheduled performance at the Grammys, without explanation.
Hours after Brown was booked on felony charges, gossip website TMZ speculated that Rihanna is the named alleged victim in the case, and that the allegation is she was assaulted with a deadly weapon.
However, the website now says that no such weapon was involved.
Other reports say that Rihanna, real name Robyn Fenty, was taken to a hospital after the alleged attack, but her mouthpiece said: "She is well. Thank you for your concern and support."
UPDATE 01.30pm: The Los Angeles Times reports that it was in fact a witness to the alleged attack made by Brown on a woman who called the cops to report the incident - possibly not the victim herself.
LAPD sources say the witness, who remains unidentified, saw a violent altercation taking place between Brown and an as yet unidentified woman on a quiet street in LA - although the woman is widely believed to be Brown's partner, Rihanna, this has not yet been confirmed.
The Times' report contradicts earlier claims that it was Rihanna, the alleged victim, who dialled 911 for assistance after Brown "fled on foot" from the scene. E! reported that two LAPD cops found Rihanna in Brown's car "beaten really badly and hysterical". Brown had reportedly taken the car keys with him and left his partner behind.
"Rihanna didn't want anyone to touch her, she was in so much pain," a snitch tells E!
LAPD detectives are said to be still gathering evidence and have not turned the case over to prosecutors yet, according to the Times. To date, Brown has been booked on a felony criminal threats charge, but other charges could be added, sources say.
Meanwhile, law enforcement sources tell TMZ that Brown's alleged attack victim, Rihanna, was left "bloody, bruised and bitten" after the altercation that led to the singer's arrest.
The website quotes a source as saying Rihanna had "huge contusions which swelled up on both sides of her forehead." The same source says she suffered "a bloody lip and nose."
An unnamed source also spoke to Radaronline.com and claimed she saw Rihanna being treated at the Cedars-Sinai Medical Center after the alleged attack.
"Rihanna was clearly very upset by what happened and I could hear her screaming. Rihanna was trying to get her point across about something. She sounded like she was crying." the snitch said.
"I left at 4pm, happy to get out of the place, something terrible had clearly happened to Rihanna."
TMZ also reports that Rihanna "may have suffered bite wounds on one of her legs and arms" - although none of this has been confirmed.
While over at people.com, a snitch reveals that Rihanna and Brown "have been fighting a lot lately."
"Lots of ups and downs. One second they're all lovey dovey and then they're fighting like crazy. They're both pretty stubborn."
And The Sun speculates that Brown's alleged attack was all down to flirtation.
