Lamar Odom's 'Roommate' - I Saw Him Do Crack

The lawyer who lived with Lamar Odom for 6 weeks in June and July tells TMZ ... Lamar was doing crack in her apartment.

Polina Polonsky is a criminal defense lawyer who met Lamar in the Spring at the Roosevelt Hotel in Hollywood. She told us on TMZ Live ... he was smoking crack and doing other drugs while he stayed with her ... but she says things really spun out-of-control when he moved out.

Polina tells us Lamar became paranoid while he lived with her ... taking the battery out of his phone because he felt he was being followed with the aid of a GPS device. He also covered the smoke detectors with paper towels.

Polina says Khloe Kardashian came banging on the door in July, barged in, took charge and took Lamar out. She received a text from Lamar shortly after he left, calling her a "groupie, junkie ... crack head." She says she knows it wasn't Lamar who sent the text ... it was Khloe.