L.A. County Sheriff's Deputy James Mee is suing his department, claiming he's the victim of religious discrimination. Mee, who is Jewish, claims he has been targeted by his superiors because of his faith.

Mee wants the jury to see a videotape of Mel Gibson in the holding cell. When TMZ broke the story about Mel's anti-Semitic rant, we referenced the video, which shows an out-of-control Mel handcuffed behind bars, complaining he had to urinate and then -- according to sources -- appearing to make an attempt to pee on the cell floor.

Law enforcement sources tell us ... the video shows Mel running around the cell and at one point even trying to scale the bars like a monkey. And when he attempted to use the phone, but couldn't get a dial tone, we're told he threw the receiver against the phone.

The County of L.A. -- the defendant -- has filed legal docs trying to block the admission of the video, arguing that it's irrelevant to Mee's religious discrimination claim and would only be used to "embarrass Mr. Gibson."

The County also believes the video would inflame the jury, because Mel is "a controversial public figure." And the County claims ... showing the video would violate Mel's right of privacy.

The judge hasn't decided whether the video is fair game.