Former NBA player and coach Butch Carter claims in an amended lawsuit filed Thursday that he was sexually abused by the doctor for the Indiana University basketball team when he was on the squad.

Carter, who went on to play for the New York Knicks, the Los Angeles Lakers and other NBA teams and was head coach of the Toronto Raptors, is the fifth former Indiana University basketball player to say he complained to legendary coach Bobby Knight about Dr. Bradford Bomba Sr.’s performing unnecessary rectal examinations on young, healthy players.

His account was included this month in an amended complaint filed in U.S. District Court for the Southern District of Indiana that accused school officials of failing to protect student-athletes from Bomba.

Carter is now a plaintiff in the lawsuit against the Indiana University trustees and longtime men’s basketball trainer Tim Garl, who is accused of having known about the sexual abuse complaints but done nothing about it, according to the lawsuit, which was originally filed in October with two plaintiffs.

Carter and the others are suing under Title IX, a federal law that requires all colleges and universities that receive federal funds to put safeguards in place to protect students from sexual predators.

The suit alleges that in 1979 at the university’s Assembly Hall, Bomba “put on gloves, lubed his fingers and told Carter to bend over the table” before he inserted at least one of his fingers into Carter’s anus.

Carter, 66, who played on the men’s basketball team from 1976 to 1980, said no other doctor had ever performed a rectal examination on him as part of a physical examination.

According to the suit, not long afterward, Carter complained to Knight, who led the Hoosiers from 1971 to 2000; to team trainer Bob Young; and to George Taliaferro, who worked in the office of the university president, “about what Dr. Bomba, Sr. had done to me.”

Carter said in the lawsuit that Young told him it was part of a normal exam.

In an earlier account included in the lawsuit, an anonymous accuser, now known to be Carter, said that before practice started in his senior year, he told Knight he never wanted to see Bomba again for medical care and that Knight responded: “You’re going to take a physical.” Carter said he told Knight that he was going to see Dr. Robert Miller, after which Knight “left it alone.”

In the earlier account, Carter said that when he told his mentor, Taliaferro, the first African American football player at Indiana University, that Bomba had “put his finger up my ass,” Taliaferro responded, “Bomba is a piece of s—.” Knight, Taliaferro and Young are all deceased.

Carter said in the lawsuit that during his senior year, he complained multiple times to Knight about Bomba’s abusive behavior during physical exams with athletes and that he fought with Knight multiple times about players being near Bomba but that to his knowledge, Knight took no action to address his complaints.

In the lawsuit, Carter said that when he played in the NBA, he received annual physical examinations from team doctors on a routine basis and that only one, during a training camp, involved a rectal examination because he had a swollen prostate at the time.

Carter said in his affidavit that he complained about Bomba to top officials in the athletic department years before the four other plaintiffs — John Flowers, Haris Mujezinovic, Charlie Miller and Larry Richardson Jr. — were allegedly abused.

“I am proud to come forward and I hope that other IU basketball players will come forward to share their experiences publicly,” Carter said in a statement Thursday.

Bomba, 88, could not immediately be reached for comment at numbers listed for him. Mark Bode, a spokesperson for the university, and William Beggs, Bomba’s attorney, did not immediately reply to requests for comment.

Bode previously referred NBC News to a statement in September that said the university had hired a private law firm to conduct an independent review of a former student-athlete’s allegations that he was subjected to inappropriate prostate and rectal exams during annual physicals with Bomba.