TULSA, Okla. - Attorneys for four ex-high school football players charged with sexually assaulting a former teammate insisted Friday that their clients were not guilty and were just "roughhousing" in the culture of their sport.

Tulsa lawyer Paul DeMuro worked to discredit the accuser and prosecutors during a news conference attended by the teenagers — who face a count of second-degree rape by instrumentation — and their families.

"It might have gotten a little out of hand, but it sure as hell wasn't rape," DeMuro said, adding that the accuser has participated in similar behaviour in a "culture of roughhousing."

Special prosecutor Matt Ballard filed the felony charges against the Bixby High School students Thursday. Three are 17 years old and one is 16. They each face up to 15 years in prison if convicted.

The Associated Press is not naming the defendants because they may be tried as juveniles.

A 16-year-old boy told investigators he was assaulted with a pool cue by several teammates in September during a team dinner at the home of the former Bixby schools superintendent. The boy said he was assaulted by one player while three others held him down, according to an affidavit.

Ballard said Thursday prosecutors are still investigating whether school officials took too long to tell police about the accusation. Prosecutors said school leadership waited eight days to report what was first deemed "an alleged hazing incident."

Investigators have said the officials' lag in reporting the assault may have jeopardized their ability to recover key evidence.

Superintendent Kyle Wood resigned from the suburban Tulsa district in December amid the fallout.

Clark Brewster, an attorney representing another one of the accused teens, said the students involved in the case were "engaging in playful behaviour that was reciprocal."

"This is a series of roughhousing and literally playful acts that had been engaged in by these young men on the football team for not just years, but maybe a decade," Brewster said.

DeMuro said the accuser continued to socialize with the teammates he had accused "as if they were best friends" and stayed the night in the same room where he reported that the assault happened.

Michelle Lowry, a spokeswoman for Ballard's office, declined to comment Friday on the news conference, but said the district attorney's office "would simply refer people to the facts of the case contained in documents filed of public record."

An Associated Press investigation published in 2017 examined sexual violence in school sports as part of a larger look at student-on-student sex assaults. The investigation found that team sexual assault is often mischaracterized as hazing and bullying and that the violence is so normalized that it persists for years, as players attacked one season become aggressors the next.

News from © The Associated Press, 2018