Da Brat just got swept up in the immigration mess ... because a juror in her civil trial LIED about being a citizen and now the trial has been derailed and the fraudulent juror is in jail.
The rapper is being sued for allegedly cracking a rum bottle over the head of a former Atlanta Falcon's cheerleader.
One of the jurors is a legal resident of Atlanta but NOT a U.S. citizen. But the dude lied to the judge and swore under oath 3 TIMES he was a full-fledged American.
The judge was LIVID ... berating the juror as he declared a mistrial and then holding him in contempt and then ordering him hauled off to the slammer.
BTW ... the bogus juror cost the county $25K.
Stay tuned for Cheerleader vs. the Rapper ... round 2.