Suge Knight Rips Tupac Murder Trial Witness Over Death Row Claims

Suge Knight is calling BS on the Tupac Shakur murder trial ... saying one of the witnesses taking the stand isn't telling the real story.

Suge joined us on "TMZ Live" Wednesday from prison and unloaded on James McDonald, who testified Tuesday in Duane "Keefe D" Davis' murder trial.

Suge flat-out denies McDonald's claim that he worked for Death Row Records.

What's more, Suge claims McDonald is an FBI informant and says he was never his head of security ... arguing there'd be plenty of proof if McDonald really worked for him.

Suge told us ... "If he did work for me, he would've had a Death Row chain. He would've had a ring. You would've seen him in pictures around us hanging out."

And Suge had another bone to pick ... this time over Snoop Dogg's upcoming biopic.

Suge initially told us he's "gonna sue the s*** out of" Snoop ... claiming one of his former lawyers handed over his personal files, which he says are now being used for the movie.

When Charles pressed him on who exactly he plans to sue, Suge clarified Snoop isn't his real target ... saying he's going after Universal instead.

Suge says he's previously had talks with Universal about doing a movie or documentary from his perspective on Death Row ... declaring, "I am Death Row."

As we previously reported, Suge has already cast doubt on the case against Keefe D ... telling TMZ he believes Tupac's murder goes beyond Keefe.

Suge's been sharing plenty of other Pac stories lately ... including his claim that some of Tupac's friends and family smoked the rapper's cremated remains after his death.