Former Yale basketball captain Jack Montague was expelled over a sexual assault allegation and plans to sue the school, his attorney said Monday.

Attorney Max Stern issued a statement saying Montague had a relationship with the woman. He said the dispute is about the last of four sexual encounters, occurring in October 2014.

The lawyer said the woman claims she didn't consent to the sex but Montague said she did and also asserts she later came back to his room to spend the night.

Stern said a Title IX official filed a complaint on the woman's behalf on Nov. 18, a university panel ruled against him and the provost upheld that ruling. Montague was expelled on Feb. 10.

Stern said Montague participated in the hearing process.

Stern called the decision "arbitrary and excessive by any rational measure" and believes Montague was made a "whipping boy" following a report on sexual assault by the Association of American Universities.

That report detailed a survey of Yale students and estimated 25.2 percent of undergraduates had experienced at least one incident that "does not meet Yale's standard for consent" and 18.1 percent had experienced an incident that involved "force or incapacitation."

"Yale has been oblivious to the catastrophic and irreparable damage resulting from these allegations and determinations," Stern said. "The expulsion not only deprives Jack of the degree which he was only three months short of earning, but has simultaneously destroyed both his educational and basketball careers."

Yale declined to comment on Montague's case, but said its process for investigation allegations of sexual assault is thorough and fair.

In 2012, Yale settled resolved a federal complaint over its responses to sexual assaults on campus and set up a system to better handle complaints.

That system, in which complaints are resolved by a university committee, includes strict confidentiality requirements.

Expulsion at Yale requires a threshold of "preponderance of the evidence" for establishing wrongdoing, lower than any criminal case.

"Only about one out of 10 cases ends in expulsion, and the decision to expel a student is made only after the most careful consideration, based on the facts and, when appropriate, disciplinary history," the school said.

Police and the local prosecutor say no criminal allegation has been filed and they are not investigating.

Stern said he plans to file a federal lawsuit in Connecticut within a month.

Montague was named captain and played through Feb. 6 despite the allegations against him, averaging 9.7 points per game.

The school said it would not remove an athlete from a team based solely on allegations, "unless a student were placed on an emergency suspension and separated from the school."

The team went 7-1 in his absence, finishing the year 22-6 and winning the Ivy League championship with a 13-1 league record. They will play Baylor on Thursday in the first round of the NCAA Tournament, the school's first appearance in the event since 1962.

The team apologized for wearing warm-up T-shirts during a nationally televised Feb. 26 game against Harvard that featured Montague's number, nickname and the word "Yale" spelled backward.

"Jack's one of our teammates, our brothers," forward Justin Sears said Sunday. "We're a team still, no matter what."

Despite uncertainty and lack of details at the time, some groups on campus condemned the basketball team for wearing the T-shirts, putting up posters that accused the team of supporting a rapist. They also used the incident to speak out on wider issues of sexual assault at Yale.

Last week, the group Unite Against Sexual Assault Yale invited people to write their feelings in chalk on tiles in front of Sterling Memorial Library. Hundreds did, with messages such as, "The only team I'm cheering for are survivors (at) Yale — dismantle men's athletic privilege."

Organizer Helen Price said the event was not meant to condemn the basketball team or Montague.

''We aimed to give people an outlet for the frustration and anger they have felt at Yale's sexual climate for a long time, the basketball incident was really just a catalyst," she said.