Los Angeles Lakers head coach Luke Walton looks on during the second half of an NBA basketball game against the Utah Jazz Wednesday, March 27, 2019.

The Sacramento Kings and the NBA have begun a joint investigation into allegations that coach Luke Walton sexually assaulted a woman.

The Kings and the league said Thursday they will be looking into the accusations contained in a lawsuit filed earlier in this week in Los Angeles by former sportscaster Kelli Tennant.

Walton's attorney, Mark Baute, has called the allegations "baseless" and says the coach will prove that in court.

Tennant contends Walton, a former Arizona Wildcats standout, attacked her when he was an assistant coach for the Golden State Warriors, which was from 2014 to 2016.

Tennant said she confided in people at the time but never filed charges because she was scared. Her lawyer, Garo Mardirossian, said because years had passed, he believed it would be difficult to file a report now with police and put together a criminal case.