Hotel Working Claim He Broke Up Fight Lindsay Lohan Denied Being In

TMZ broke the story ... Marisa Dugas went to the L.A. County Sheriff's Dept. and filed an incident report, claiming she was at Smoke and Mirrors inside The Standard Thursday night when she approached Lindsay's table and started talking to a guy, and Lindsay allegedly pushed and shoved her. Lindsay insists she was at home the entire evening.

The man who worked that night tells TMZ ... he saw Lindsay in Smoke and Mirrors sitting with a group of people. He says Marisa sat down near them and began speaking with one of the guys. The man says people in the group started throwing ice at her. Marisa got upset and a scuffle erupted. He says Lindsay was part of the scuffle and he broke it up.

The guy says the woman was escorted out of the club, where she cried hysterically and then said Lindsay hurt her, but she refused medical attention.

There are no pictures that have surfaced of Lindsay at the Standard Thursday night, but the man says there is a surveillance video showing the back of the hotel, where Lindsay pulled in and later left. We have confirmed the man has spoken with cops, although we do not know how much detail he divulged.

Sources tell us the L.A. County Sheriff's Department has already requested the surveillance tape three times from the hotel -- but hotel management is refusing to give it up. It's unclear why.