Washington: The reference of alleged "misconduct" mentioned in the indictment of former US House Speaker Dennis Hastert is of a sexual nature involving a male individual when Hastert was a high school wrestling coach and history teacher in Yorkville, Illinois.

Hastert's former colleagues and associates expressed surprise over allegations that he was involvement in the disbursement of $1.7 million in hush money payments in order to conceal alleged misconduct from a period before Hastert decided to enter politics.

The school district that employed Hastert from 1965 to 1981 as a high school history teacher and wrestling coach noted it "was first made aware of any concerns regarding Hastert when the federal indictment was released" Thursday.

The indictment showed that Hastert's time at Yorkville, in Illinois, is "material" to the allegations against him and the U.S. Attorney's investigation. The indictment, however, did not mention the alleged misconduct.

A statement released by Yorkville Community Unit School District #115 added it "has no knowledge of Mr. Hastert's alleged misconduct, nor has any individual contacted the District to report any such misconduct. If requested to do so, the District plans to cooperate fully with the U.S. Attorney's investigation into this matter."

A spokesman for Dickstein Shapiro LLC, the lobbying firm where Hastert worked in 2008 after leaving Congress, confirmed in a brief statement that "Dennis Hastert has resigned from the firm."

Ron Safer, a former U.S. prosecutor in Chicago who is now in private practice, said the indictment "is weird for a hundred different reasons."

"If you are trying to keep everything secret, you don't indict," Safer told ABC News. "Because eventually this information will have to come out either when he pleads, because that's public, and a factual basis will have to be revealed," Safer told ABC News. "I cannot imagine a judge sealing that. ... The public has a right to this kind of information. This guy is a public official."