Brown's attorney, Mark Geragos, confirmed Thursday that the R&B singer had been taken by federal marshals to the San Bernardino County jail while he awaits transportation to Washington, D.C. Inmate records show he was taken from "LA cell block" at 5:15 p.m. Tuesday.
Law enforcement sources said he was set to be flown out to the East Coast on Thursday, the same day a hearing had been scheduled for a motion by Geragos seeking to block Brown's transfer to federal authorities, arguing it would hurt his ability to confer with his client before the trial.
Geragos had also sought permission to transport the singer himself, but as soon as the motion was filed, the attorney said federal authorities took his client.
Last week, a Washington judge authorized federal marshals to bring Brown to court for an April 17 trial, in which he faces a misdemeanor assault charge for allegedly striking a man trying to take a picture of him outside the W Hotel.
But Brown was ordered jailed in March by Los Angeles County Superior Court Judge James Brandlin after the Grammy winner was ejected from a court-ordered treatment for his 2009 conviction for beating his then-girlfriend, singer Rihanna.
In 2009, Brown was sentenced to five years' probation, community labor and domestic violence counseling for assaulting Rihanna after they left a pre-Grammy party. Brandlin could sentence Brown to up to four years in prison if he determines that the singer violated his probation.
Brandlin said Brown was kicked out of rehab because he allegedly touched a woman, failed to take a drug test and made threatening statements during a group session.