Law enforcement sources tell TMZ a L.A. County Superior Court judge has just signed a "5150," meaning Britney Spears is on a three-day psychiatric hold at the UCLA Medical Center.
We're told there is a "good possibility" that it will be extended to 14 days. We've also learned there have been several parallel attempts to get Britney on a 5150. Her lawyers, Anne Kiley and Tara Scott, secured a new psychiatrist late last week -- he's the one who triggered the 5150 last night.
Whether Sam or her parents are the ones that will be making the medical decisions is still to be determined, another heated topic between the Spears clan.
UPDATE: TMZ has learned Britney's parents have won round one in the tug of war with Sam Lutfi. We're told the doctors at UCLA are now "fully cooperating" with the parents in the treatment of Britney Spears, however, the war probably is not over until a judge signs an order as to who has control.