Teachers’ union officials in 2010 directly e-mailed D.C. Schools Chancellor Kaya Henderson telling her that the principal of a D.C. elementary school had reported seeing employees cheating on a city-issued test, according to e-mails obtained by the Associated Press through a Freedom of Information Act request.

The e-mails — which offered no specifics about the allegations and said the principal’s claims were uncorroborated — show that Henderson quickly referred the matter to the school system’s then-chief of accountability, Erin McGoldrick, sending an e-mail about the matter less than two hours after she received the report. Henderson asked McGoldrick to be in touch with union leaders about the allegations and wrote to the union official: “Thanks for alerting us.”

McGoldrick replied, writing that the school system had already been informed of allegations at the school, Northeast Washington’s Noyes Elementary, and was in the midst of finalizing an investigation.

It’s not clear from the e-mails — in early November 2010 — whether McGoldrick knew that the allegations the union officials forwarded were new and had occurred only the day before; the union officials’ e-mails don’t specify a date. At the time, the school system was in the midst of investigating older cheating allegations at Noyes.

Adell Cothorne, the principal of Noyes at the time, left the school in 2011 and went on to file a whistleblower lawsuit claiming that school system officials ignored her efforts to raise an alarm about cheating.

Cothorne said that in 2010, she immediately reported the alleged cheating incident by phone to two central office administrators, who never investigated it. Henderson disputed that account at the time, saying there was no record that Cothorne had reported any such incident to school system officials.

The e-mails show instead that union officials contacted Henderson, and that union officials also investigated. Clay White, who was then the union’s chief of staff, said the next day that union leaders directed two field representatives to fully investigate the matter, according to an e-mail White sent to Henderson, McGoldrick and others.

The whistleblower suit prompted an investigation by the U.S. Department of Education, which did not find evidence to support Cothorne’s claims. Cothorne withdrew the case last year.

Cothorne told the Associated Press that the union’s 2010 e-mail exchange with Henderson shows that officials didn’t take cheating seriously because they didn’t follow up with her to ask what she had seen. School system officials said they take every cheating allegation seriously, and pointed out that Noyes has been the subject of multiple investigations during the past several years.

“It is perhaps the most investigated school in the city,” Pete Weber, the school system’s chief of data and strategy, said in an interview Thursday. Weber said that the school system investigated Cothorne’s claims when they became public in 2013 and found no substance to them.

Noyes and its fast-improving test scores became a model for success during the tenure of former Chancellor Michelle Rhee. But the school came under scrutiny after a 2011 USA Today investigation found an unusually high number of wrong-to-right erasures at Noyes and more than 100 other schools in the city.

Educators’ jobs and merit bonuses depended on improving test scores, and between 2007 and 2009, some schools saw huge increases that later reversed after test security was tightened.

Several employees have been fired for cheating at Noyes, but investigators have said they did not find evidence of the widespread cheating suggested by USA Today’s report.