July 20 (Bloomberg) — A National Basketball Association referee is under investigation by the FBI for allegedly betting on games, the head of the referees association said.

“These accusations, if true, are extremely serious and we have been in discussions with the NBA regarding this matter,” Lamell McMorris said in an interview. “In light of the fact that this is an ongoing federal criminal investigation, we have nothing further to say at this time.”

The NBA said in a statement that the Federal Bureau of Investigation has asked it not to comment. FBI spokesman Neil Donovan didn’t immediately return calls for comment.

The New York Post reported today that a referee, whose name hasn’t been disclosed, was working with organized crime to affect the outcome of games.

The FBI is set to arrest the referee, who allegedly wagered on games the past two seasons, along with others who profited from the scheme, according to the Post, citing people it didn’t name. The referee bet on games he officiated, the Post said.

Baseball has been involved in some of the biggest sports gambling scandals. Members of the 1919 Chicago White Sox were banned from the sport for taking money to lose the World Series. Pete Rose was banished in 1989 for betting on the Cincinnati Reds while he was managing the team.

In college basketball, players from schools including the City College of New York were implicated in rigging games in the late 1940s, and organized crime figure Henry Hill plotted with Boston College players in the late 1970s.

NBA referees have been under federal investigation before. Several officials pleaded guilty to tax evasion charges in 1998 after an Internal Revenue Service probe revealed a scheme of exchanging first-class airline tickets for cheaper ones and pocketing the difference without reporting the extra income.