Diddy Expert Claims Multiple Versions of Cassie Video Show Distortion

Multiple videos of Diddy beating up Cassie in a hotel hallway show "significant distortion" ... this according to a forensic video technician working for the rapper's team.

Conor McCourt -- a former New York City Police officer with years of experience analyzing video footage -- says in a sworn deposition that he has reviewed the clip CNN published, as well as another video of surveillance footage that was recorded on an iPhone 6 directly.

It's a bit confusing, but basically McCourt takes issue with both versions he's seen, first claiming the CNN vid appears sped up because it was converted from one file type to another in a process called "transcoding" ... which he claims adds, subtracts and duplicates frames.

McCourt then goes on to say the video shot with the iPhone 6 makes Diddy look larger and wider than he was at the time ... contributing to a more domineering appearance.

CM notes timecode issues between two of the videos he reviewed ... claiming at least three timestamps all depict different times for the same moment, while at other times the same timecode in two different videos seems to show two different moments.

McCourt says the timecode issues make it so "a viewer does not know what happened during those numerous breaks in video." He ultimately concludes that "none of the available video files are accurate and reliable copies of the original." Diddy's team also wants a pre-trial hearing about the tape.

As we told you last month ... Diddy's team and prosecutors filed a joint letter to the court -- claiming CNN purchased the original video, altered it and then destroyed the original.

CNN denied altering and then destroying the footage ... claiming instead the OG copy was retained by the source. Prosecutors later said they had a copy of the original tape -- which appears to be the iPhone 6 video McCourt reviewed.

Diddy has pled not guilty to two counts of sex trafficking, two counts of transportation to engage in prostitution, and one count of racketeering. His trial is scheduled to begin next month.