"Vanderpump Villa" star Marciano Brunette is making moves to get his hands on unaired 'Secret Lives of Mormon Wives' footage ... to help prove his case against cast member Demi Engemann and the production company that made the show.

According to court docs obtained by TMZ, Marciano is fighting the effort of Jeff Jenkins Productions -- the producers behind 'Mormon Wives' -- to have his defamation lawsuit thrown out of court.

Marciano said he's been asking producers to fork over the unaired show footage related to Demi's allegations of sexual assault. In addition, he wants to see the producers' internal communications about the sexual assault narrative and its editorial decisions.

Marciano insists there's no way his lawsuit should be kicked out on summary judgment before he has a chance to see all the evidence the producers have in their possession, which might be relevant to proving his case.

As TMZ first reported, Marciano sued Demi and producers after she claimed he sexually assaulted her. He claimed the incident was consensual and that Demi knows that.

Jeff Jenkins Productions asked the court to throw the case out before any lengthy discovery about the issues, arguing Marciano signed a binding release to appear on the show that blocks his ability to sue over it now.

The lawsuit is ongoing.