Atlanta public schools is again facing allegations of cheating, this time at North Atlanta High, where investigators from the district’s Office of Internal Compliance are looking into claims that grades have been changed, school spokesman Stephen Alford confirmed Thursday.

Alford would not say when the investigations began at the school, which has been at the center of a controversy since superintendent Erroll Davis removed 6 administrators from the school on Oct. 5, citing poor academic performance at the Buckhead high school.

The spokesman said he could not characterize the nature of the cheating. “It could range from teachers changing grades on student assignments to teachers changing final grades on report cards, or mid-term exams,” said Alford.. “We’re not in a position to comment any more than that since it’s an open investigation.”

The school system has put stricter controls in place since the 2009 Criterion-Referenced Competency Tests cheating scandal that rocked the district, implicating about 180 educators, some of whom this year are appealing their cases before tribunals after Davis moved to have them fired.

This week the Atlanta school board moved to delay until December deciding whether to renew the contract of Davis, who has come under sharp criticism from some parents and students for handling of the removing the six administrators from Atlanta High.