'Saw X' Director Says Cops Were Called During Editing Session

The new 'Saw' movie is apparently a bloody nightmare -- so much so, that someone called the cops while they were putting the film together in post-production ... so says the director.

Kevin Greutert told the harrowing tale to NME ... saying the key editor for 'Saw X,' Steve Forn, got paid a visit by the 5-0 while he was splicing up the film -- particularly, during sound design for a really gruesome scene ... where a character gets their eyes sucked out.

Here's how KG put it ... "There was a knock at the door. We have the doorbell [camera] video of the police walking up, [Forn answering the door] and the police saying, 'The neighbours [have been] calling and saying someone’s being tortured to death in here.'"

Forn apparently replied, "'Actually, I’m just working on a movie… You can come in and see it if you want?'" The police declined ... just wanting to make sure everything was kosher.

Greutert adds, "It’s a pretty funny story ... Plus Steve is such a mild mannered guy. I can only imagine the look on his face when he realised what was happening!"

Hopefully that's enough to make people realize ... this latest 'Saw' installment is supposed to be one of the most brutal ones yet, not to mention the best overall to come along in years.

The reviews for 'Saw X' have been glowing ... and some say it's a true return to form.