The report on 1050 ESPN Radio in New York said Donaghy will provide prosecutors as many as 20 names of other NBA officials and will detail their involvement in some form of gambling, believed to include betting in casinos.

The offenses may not include criminal activity, according to the report, but could violate NBA policy and lead to firings that would decimate the officiating staff. Twenty referees would make up about a third of the league's roster.

"This incident is an isolated incident and our folks are of the highest integrity and character and we're open to sitting down with the NBA to discuss measures that help make sure that the integrity of the game is maintained," said Lamell McMorris, head of the referees union.

"As far as I know, our folks are of the highest character. This situation has been isolated to one individual."

NBA spokesman Tim Frank said the league had no additional information and would not comment. Commissioner David Stern said last month that he believed no other officials were being investigated for criminal activity, calling Donaghy a "rogue, isolated criminal."