Justin Bieber is trying desperately to stop authorities from leaking a video -- that shows him taking a leak in his jail cell.

The Bieb's lawyers want to stop the release of video that was collected after his arrest in Miami last month, some of which made its way to the tabloids a few days ago. Though the already aired tapes show Justin being patted down and question, the trove also includes some shots that focus on his "intimate parts."

A source tells TMZ, "Justin is seen several times stumbling around while he was taking his tests, as if he had a problem with his balance... [The video] also shows Justin taking his various tests and eventually taking a [leak]."