According to the Kansas City Star, police are looking into claims made by a restaurant owner in the area as well as one of her waiters -- who are alleging Jackson both sexually assaulted and physically assaulted them last weekend at the Aspens Restaurant and Lounge.

The owner -- 40-year-old Aspen Vaughn -- provided KCS and cops with surveillance footage she says was captured last Saturday ... when this alleged assault happened. In the clip, you can see a man, whom she says is Jackson, wrap her up in his arms and forcibly kiss her.

It doesn't just happen once, BTW ... you see this man go in for kisses at least twice.

Vaughn says she believes Jackson was intoxicated, but nonetheless ... his advances were unwelcome, which she says she made clear to him in the moment. Earlier that same night, one of Vaughn's wait staff claims Jackson shoved him out of a private room he was dining in with his entourage -- this after the waiter smelled weed and tried to get them to stop.

The waiter alleges Jackson and his crew shoved this guy out and told him to scram. Apparently, Jackson frequents this place a lot and knows the owner's step-daughter -- at least that's what she's saying. But, in this case, she claims he crossed several lines.

Vaughn says she and her hubby kicked Jackson and his friends out after the alleged forcible kiss, and that cops were called shortly thereafter. As far as we know, Jackson hasn't been arrested yet ... but his attorney has spoken out and defended his client, saying he's innocent.

His lawyer, Brandan Davies, says ... "Jackson has done nothing wrong. Our investigation has revealed substantial evidence refuting the claims of Jackson’s accuser including the statements of several witnesses. We have reached out to law enforcement to provide the fruit of our investigation so that they may have a complete picture of the matter."

The Kansas City Star says Jackson is under investigation for the alleged sexual assault of the woman, but not for the alleged assault of the waiter. It's unclear if the waiter is going to press charges, but Vaughn says the cops already told her they're pursuing the alleged kiss without or without her help ... and she says she's going to cooperate in their probe.