Kelli Tennant and her lawyer hold a news conference to detail the 2014 incident in which she alleges she was sexually assaulted by Luke Walton. (2:01)

The Sacramento Kings and NBA announced Thursday that they have started a joint investigation into the allegations made in a civil suit against coach Luke Walton that he sexually assaulted a woman in 2014.

"The Kings and the NBA take these allegations very seriously and will collaborate to conduct a complete and thorough investigation," the team and league said in a statement.

The Kings' investigation will be led by Sue Ann Van Dermyden, the founding partner of Sacramento law firm Van Dermyden Maddux, and Jennifer Doughty, a senior associate attorney at the firm.

The NBA's investigation will be led by Elizabeth Maringer, the league's senior vice president and assistant general counsel, integrity and investigations.

Kelli Tennant -- a former host on Spectrum SportsNet LA, the Lakers' regional sports network -- alleges that Walton, then an assistant with the Golden State Warriors who was in Los Angeles on a road trip, sexually assaulted her in a Santa Monica, California, hotel room. Tennant's attorney says that happened in 2014.

On Tuesday, Tennant said she was terrified Walton was going to rape her and that she hadn't gone public with the allegations sooner because she was scared.

Tennant had a working relationship with Walton stemming from his time as a guest analyst on Spectrum. In the lawsuit, she alleges that she met with him at the Casa Del Mar Hotel to drop off a copy of her book, "a guide for student-athletes making the transition into a world after sports," for which he wrote the foreword.

Tennant alleges that Walton invited her up to his room, where he pinned her to the bed and forcibly kissed and groped her.

Tennant said she did not go to the police or talk with officials at Spectrum at the time because she was only 25 and was scared.

Walton's attorney, Mark Baute, called the allegations "baseless" and said Tennant was "an opportunist."

"These claims are false and Luke's innocence will be proven in court," Baute said in a statement Wednesday. "[Tuesday's] press conference was a poorly staged attempt to portray the accuser as a viable spokesperson for an important movement. Her lawyers want to create a public circus to distract from their complete lack of evidence to support their outrageous claims. We will not try this case in the media or pay them a dime."

The Kings hired Walton earlier this month, shortly after he and the Lakers mutually parted ways.