One in three high-profile athletes receive abusive messages from individuals with a “betting interest,” and more than 540 men’s and women’s college basketball players received similar abuse, including death threats, during championship tournaments in March, the NCAA said in a release Friday.

The NCAA looked at athletes participating in sports that attract the most betting interest — football and basketball, among others — and found that online abuse is widespread. Signify, an artificial intelligence company and NCAA partner, covered 1,000 Division I men’s and women’s college basketball players, 64 teams, more than 200 coaches and 120 NCAA game officials during March Madness. The analysis, which is part of an NCAA initiative aimed at combating online abuse and harassment, found 4,000 posts or comments that were confirmed to be abusive or threatening during March Madness.

The NCAA said the data showed women’s basketball players received approximately three times more overall threats than men’s players and that 15-25% of abuse directed at players, coaches and officials who are involved in the most popular college sports was related to betting.

“Individuals who harass athletes, amateur or professional, over a sports bet should not be tolerated,” Joe Maloney, senior vice president of strategic communications for the American Gaming Association, told ESPN in a statement. “Importantly, the legal sports wagering market is providing the transparency critical to discuss solutions to reducing player harassment for the first time — an opportunity illegal market actors do not provide. We look forward to continuing our dialogue with the NCAA, professional leagues, and other stakeholders on the universal shared goal of reducing athlete harassment.”

In March, Armando Bacot, a forward on the North Carolina men’s basketball team, told reporters he received dozens of direct messages on social media criticizing him for his performance in the Tar Heels’ win over Michigan State in the second round of the NCAA tournament.

“It’s terrible,” Bacot said. “Even at the last game, I guess I didn’t get enough rebounds or something. I thought I played pretty good last game, but I looked at my DMs, and I got like over 100 messages from people telling me I sucked and stuff like that because I didn’t get enough rebounds.”

The data released coincides with the NCAA’s efforts to ban sportsbooks from offering prop betting on college players. Prop betting includes wagers such as the over/under on a player’s points or rebounds. Ohio, Louisiana, Maryland and Vermont have passed recent legislation banning prop betting on college players, and more states are considering the issue.

Joe Brennan, a longtime internet gaming consultant and now executive director for online sportsbook Prime Sports, believes the NCAA is looking at the issue “from the wrong end of the telescope.”

“This is a social media problem first and foremost,” Brennan said. “The NCAA demanding the banning of college player props is a distraction from the root causes and likely solutions. Abusive speech towards teams and players is a sad reality in competitive sports. … It’s unfortunate that sports betting has now also become another subject in this, but it certainly didn’t start it.”