The executive director of the Memphis Academy of Health Sciences, one of city’s oldest charter networks, was fired last week following an internal investigation.

Corey Johnson was placed on suspension with pay last month and fired on Dec. 3, according to Ricky Wilkins, the network’s lawyer. Johnson had served as the executive director for about five years.

Wilkins declined to tell Chalkbeat what the investigation revealed or why Johnson was fired. Chalkbeat attempted to reach Johnson Wednesday, but the phone number was disconnected.

The charter organization, founded by 100 Black Men of Memphis Inc. in 2003, runs a middle school and a high school in North Memphis with about 700 students total. Johnson oversaw principals at both schools and was the main liaison between the schools and the board of directors.

The firing comes more than a year after Johnson was at the center of a controversy including firing a principal for low test scores and then the firing of an ACT prep teacher who publicly defended the principal. At least two lawsuits have been filed in the aftermath, including allegations that the charter network misspent funds.

The Johnson inquiry began after Wilkins said the state comptroller’s office approached the academy to audit its books and records.

“MAHS in response conducted its own internal investigation and during the course of that investigation, MAHS determined it best to separate Mr. Johnson from his employment with the school,” Wilkins said Wednesday.

Derrick Joyce, a founding board member, is the interim executive director, a position he has held at least once before in 2014.