Justin Bieber -- Cops Say Video Shows Him Peeing in Jail Cell

Justin Bieber is on the offensive after embarrassing video surfaced of him getting patted down in jail following his DUI arrest in Miami Beach -- TMZ has learned, he's now begging for ALL police video to stay out of the public eye ... including footage of him urinating in his jail cell.

The pat down video surfaced last week -- showing Bieber getting the old "spread 'em" routine -- and his lawyers are upset ... now asking the court to block police from releasing any more footage from the singer's arrest without showing it to them first.

Not only does the footage paint a negative picture of Bieber -- for obvious reasons -- Bieber's lawyers claim additional video inside the station shows the singer in "various states of undress, which show intimate personal parts" of his body.

And law enforcement sources tell TMZ, the "personal parts" in question are revealed while Bieber urinates in his holding cell.

A source who saw the video tells us, "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 piss."

The source adds, "The stumbling and going to the bathroom is obviously reason enough for his attorneys to request it be sealed ... If I was trying to paint a picture that my client was innocent ... I wouldn’t want a video of him stumbling around and looking out of it to go public either."

Not like it's anything we haven't seen before.