Police confirmed Monday that the former Sugar Grove Township supervisor is the subject of an ongoing investigation.

Sugar Grove Police Chief Ron Moser said a criminal complaint against former Township Supervisor Dan Nagel has been filed with police. Nagel resigned from his post Oct. 31.

“A criminal complaint has been filed, and this is an ongoing investigation,” Moser said. “I cannot comment further.”

In a letter, Nagel said he was resigning due to personal and family reasons. He served as supervisor for seven years and as a trustee for 31 years.

“It has been a sincere pleasure serving you as supervisor and trustee of the Township of Sugar Grove for the past 38 years,” Nagel wrote.

On Monday, Sugar Grove Townshii Trustee Scott Jesseman confirmed that he filed the criminal complaint with Sugar Grove police.

Jesseman, who was appointed to the board by Nagel, said he filed a Freedom of Information Act request in June regarding checks made payable to Nagel. Jesseman said documents show thousands of dollars in “questionable charges.”

Documents show that some of the payments made to Nagel are missing receipts. Other receipts don’t show what was purchased at specific restaurants or stores. According to Illinois Township code, a supervisor must keep receipts of expenditures.

After a meeting with Trustee Harry Davis and another trustee, Nagel decided to resign. On the same day, Oct. 31, Nagel wrote a $4,000 check payable to the township , Jesseman and Davis confirmed.

“Who writes a check back if you didn’t do anything?” Jesseman said.

In 2009, Nagel was paid $3,000 from the Road and Bridge Fund for auditing the road district books. Jesseman and Davis said the board did not approve that expenditure.

According to the Township Officials of Illinois organization, a supervisor can be paid between $100 and $1,000 per year for serving as road district treasurer. But that amount must be set at the same time as the rest of their salary. Illinois law dictates that elected officials cannot alter their salary during their term.

Davis, who has been a trustee for eight years, said Nagel needed to resign.

“Funds may have been spent without the entire board agreeing to it,” Davis said. “Were they done to Sugar Grove Township’s benefit? (That’s) yet to be known.”

Township Trustee Steve Ruh declined to comment, citing the pending investigation. Trustee Scott Hester could not be reached Monday.

Nagel could not be reached Monday.