Former Indiana basketball coach Bobby Knight. Chip Somodevilla/Getty Images

Former college basketball coach Bobby Knight was the subject of an FBI investigation after he was accused of groping four women during a July 2015 trip a little-known US spy agency, according to an in-depth report from Craig Whitlock of The Washington Post.

Knight denied any wrongdoing and the FBI closed the case without charges more than a year after Knight was accused of inappropriately touching the women during a trip to give a speech at the National Geospatial-Intelligence Agency (NGA) at Fort Belvoir, Virginia. However, the Post story raises questions about how the case was handled.

According to the report, the FBI documented four incidents during its investigation. However, two of the women declined to file complaints and a third woman did not comment to the Post. The fourth woman has filed a sex and race discrimination complaint against the NGA, "alleging that she was denied promotion and given poor performance reviews in retaliation for reporting that she was groped by Knight," according to the Post.

Here are how the four incidents were described by the Post:

1. One NGA employee who the Post said did not file a complaint picked up Knight at a train station. In the car, the woman recounted to the Post, Knight said "he could tell I was an athlete from my legs." According to the woman, he then touched her shoulder. According to the Post, she described the encounter as "uncomfortable, but she chalked up his behavior to age."
2. A second NGA employee was in an autograph line when she says Knight greeted her "with a smack on the buttocks," according to the Post. The woman referenced Knight's age during an interview with the Post, and likened his behavior to that of "a drunk uncle." She also told the Post "I just let it go. Honestly, my job was just more important than what was going on in that situation."
3. A third woman, who the Post said has filed the discrimination complaint, accused Knight of putting his arm around her and groping her buttocks "multiple times," according to the Post. That alleged incident was witnessed by a male NGA employee who later told supervisors that he said to the woman at the time, "Bobby Knight hit you on your ass! He is a dirty old man!"
4. A fourth alleged incident was witnessed by the third woman. According to the Post, she described an incident in which Knight was "putting his hands on the sides of her chest and lifting her off the ground." That fourth woman did not speak with the Post, and it is unclear if she ever filed a complaint.

Complicating matters is that Knight is a close family friend of the head of the NGA, Robert Cardillo — who asked Knight to give the talk — and Cardillo's father, Richard Cardillo, a retired Army brigadier general. The elder Cardillo was in the car during the first alleged incident, the Post said.

The report also raises questions about how the case was handled.

The allegations were initially handled by the Army’s Criminal Investigation Command. However, the case was transferred to the FBI after a month due to Knight's status as a civilian. According to the Post, the case was inexplicably dormant for eight months until the FBI re-interviewed the women.

In July, 2016, a year after the alleged incidents, the FBI interviewed Knight for the first time. According to Knight's lawyer, Knight was unaware there was even an investigation until the interview. FBI agents were reportedly told to tell Knight "if there were any more complaints he could be arrested."

From the post:

"Knight denied any wrongdoing to the FBI. His attorney, James Voyles, said that it was 'the first and only time' Knight had been interviewed by law enforcement agents about his visit to the NGA and that he had been unaware he was under investigation until the FBI contacted him."

"There is absolutely no credible evidence to support this in our opinion, these allegations," Voyles told the Post. "[The FBI agents] reported to their superiors that there was no basis for any further action, period."

When reached by Business Insider, Voyles reiterated that the case was closed by multiple agencies.

"There was no credible evidence to support any of the allegations," Voyles said. "T he matter was investigated by both the FBI and the Army and Mr. Knight  and all the woman were interviewed by those agencies as well as the  General who was with Mr. Knight the entire time and the matter was  closed by both agencies."

The Post attempted to contact Knight. His wife responded, saying, "Bob did nothing wrong and there is NO evidence to prove that he did. Case closed."

You can read the full story at The Washington Post.