Joe Tacopina, who now reps Myla, tells TMZ ... Kris and his lawyer have been on a search and destroy mission against his client, trying to hide the fact that they have been in a relationship for 5 months.

Tacopina says Kris' lawyer called the hotel manager last week and made the claims. Tacopina believes Kris and his lawyer wanted to get Myla fired, to make a point that she had better shut her mouth about her relationship with Kris ... or else.

By the way, sources connected with Kris confirm his lawyer made the call.

We're told hotel management investigated and quickly determined the allegations were baseless.

Tacopina tells us ... a defamation case against Kris now looms large, and he had better apologize quickly for what he says is shameful, vindictive conduct.