The University of Oklahoma said Friday it disciplined 25 students after its investigation into video showing members of a fraternity engaged in a racist chant.

David Boren, the university's president, said investigators interviewed more than 150 people involved with Sigma Alpha Epsilon and found the chant was learned by chapter members while on an SAE national leadership cruise four years ago, Fox affiliate KOKH-TV reported.

Members of the Sigma Alpha Epsilon fraternity at the university were caught on video engaging in the chant that referenced lynching and used a racial slur in asserting that African-Americans would never become members.

The chant was then brought back to the university's SAE chapter and taught to pledges as part of the formal and informal pledge process, according to Boren.

He said 17 students on the bus and eight others were disciplined as a result of the investigation, according to the station. Boren also said he wrote a letter to the executive director of SAE to determine what steps it is taking to determine the extent of the chant and how they will remedy it.

A representative from the national chapter could not be reached for comment Friday. 

The university began the probe into the now-defunct chapter after the video's release. The school has since severed ties with the fraternity, closed the house and expelled two students. An attorney representing the local chapter, Stephen Jones, said Wednesday an agreement was reached with university officials that calls for no more expulsions of fraternity members.

Click for more from KOKH-TV