The former principal of a Mobile high school who resigned Monday after being placed on administrative leave was reportedly under investigation for allegedly mismanaging $100,000 in school funds.

Ex-Vigor High School principal Gerald Cunningham was placed on leave in March, WKRG reported. At the time, it was unclear why he was placed on leave.

Cunningham’s resigned on Monday, which made the reason for his leave public record.

A spokeswoman for Mobile County Public Schools said Vigor was placed in receivership in January, meaning all purchases made by the school first had to be approved by the central office, WKRG reported.

“MCPSS conducted a lengthy financial audit and determined that there was mismanagement of school funds at Vigor High School in the amount of about $100,000,” the spokeswoman said, according to the station.