NORMAN, Okla. (AP) — Members of a University of Oklahoma fraternity apparently learned a racist chant that recently got their chapter disbanded during a national leadership cruise four years ago that was sponsored by the fraternity’s national administration, the university’s president said Friday.

President David Boren said the school interviewed more than 160 people during its investigation into members of its now-defunct Sigma Alpha Epsilon chapter who were captured on video taking part in the chant, which included references to lynching, a racial slur and the promise that the fraternity would never accept a black member.

“That chant was learned and brought back to the local chapter,” Boren said at a news conference in which he disclosed the school investigation’s findings. “Over time, the chant was formalized by the local chapter and was taught to pledges as part of the formal and informal pledgeship process.”

A statement released Friday by the Evanston, Illinois-based national Sigma Alpha Epsilon Fraternity said its own investigation is ongoing but confirmed the chant likely was shared during its annual six-day retreat. SAE’s Executive Director Blaine Ayers said in the statement he believes some members shared the chant during an informal “social gathering” outside of the normal slate of classes, seminars and other educational functions.

“But our investigation to date shows no evidence the song was widely shared across the broader organization,” Ayers said.

Boren said about 25 members of the school’s SAE chapter will face punishment ranging from two expulsions the school announced previously to mandatory community service and cultural sensitivity training. The video, which surfaced earlier this month, showed fraternity members yelling the chant on a chartered bus while headed to a formal event at an Oklahoma City country club with their dates, Boren said.

Boren said the investigation found alcohol was “readily available” at the fraternity house before the start of the event and that about a dozen high school students whom he described as “potential recruits” were also on the bus.

Beginning in the fall, Boren said all current and future OU students will be required to take diversity training.

After the video surfaced, Boren severed ties with the local chapter and shuttered the fraternity house.

One of those students, Levi Pettit, apologized at a news conference Wednesday in which he was flanked by black community leaders. Pettit, who is from the Dallas enclave of Highland Park, answered a few questions from reporters but declined to say who taught him the chant.

“The truth is what was said in that chant is disgusting ... and after meeting with these people I’ve learned these words should never be repeated,” Pettit said.

A second student from the Dallas area, Parker Rice, also issued a statement apologizing for his role in the chant.

Isaac Hill, the president of the university’s Black Student Association, met earlier Friday with Boren and seven student leaders from the defunct OU chapter, along with some student athletes and members of historically black fraternities. Hill, a junior from Midwest City, said each fraternity member apologized personally for his role in the chant.

“I believe the students were very sincere in their apologies, and we are all good with that,” Hill said.

Also Friday, Boren sent a letter to Ayers asking the national fraternity director what steps he was taking to investigate the origin of the chant. In the letter, Boren wrote that while there is no indication the chant was part of the formal teaching of the national organization, “it does appear that the chant was widely known and informally shared amongst members on the leadership cruise.”

SAE’s national leadership disbanded the OU chapter after the incident and announced it was taking steps to become more inclusive, including by requiring all members to go through diversity training and by setting up a confidential hotline for people to report inappropriate behavior.

SAE began collecting racial and ethnic data in 2013. About 3 percent of SAE’s reporting members identified as African-American and 20 percent identified as non-white, according to Ayers.