Christina Aguilera was arrested in the small hours of this morning and booked on a misdemeanor charge of public intoxication. Meanwhile, Aguilera's boyfriend Matt Rutler was also arrested by police at the same time for allegedly driving under the influence...

LA police sources claim Aguilera was "extremely intoxicated" and "unable to take care of herself." Hence the arrest, presumably.

Another source has claimed to TMZ:

"If the driver had NOT been arrested for DUI, [Christina] would have never been in trouble."

Rutler's bail was set at £15,000. TMZ allege he was pulled over when officers noticed he was driving erratically.

It seems like it's all been downhill for Aguilera since she split with husband Jordan Bratman. First there was her film Burlesque (where she also happened to meet set assistant Rutler), followed by reports of drunken antics ever since, including rumours she passed out pissed in Jeremy Renner's bed during his 40th Birthday party. And she wasn't even invited! 'Concerned friends' have said she'll be in rehab by next month. Or possibly sooner now.

Update:

Michael Thomas of West Hollywood Sheriff's Department has since said of Aguilera and Rutler's arrest:

"They were cooperative, no problems at all."

He added Aguilera was taken into custody "for her own safety. It's kind of a welfare 'arrest.' Not a criminal arrest. She was intoxicated -- too much to be in public. No one was available to take care of her, because the person she was with was arrested for drunk driving. When it's determined she's sober, she'll be released."

From the sound of it, that could take a while...