PORTLAND — Portland Superintendent of Schools Emmanuel Caulk on Wednesday responded to what he called “unfounded speculation and innuendo” surrounding the sudden departure of former Deering High School football coach Matthew Riddell the night before the school’s 103rd annual Thanksgiving Day game against Portland High School.

The superintendent said Riddell, a Lewiston High School graduate, was not terminated, nor did he resign.

“He is simply not re-applying” for the stipended coaching position appointed annually, Caulk said.

Caulk said the school department was still conducting an internal investigation into an allegation made against Riddell when Riddell emailed school administrators just after 2:30 p.m. on Nov. 26, to notify them of his decision.

“As we discussed, two members of my family are very ill, and therefore, I will not be able to reapply to the team next year,” Riddell wrote in the email provided to the Bangor Daily News by Caulk. “I also do not believe I will be at the game tomorrow … Thank you for all you have done for me and the football program.”

Ninety minutes after receiving Riddell’s email, Caulk shared the news of his sudden departure with parents of Deering High football players via email. The email Caulk provided to the Bangor Daily News was designed to clarify “misinformation,” the superintendent said.

On Tuesday, Caulk said Riddell was not coerced into his decision not to coach the final game of the season or not to reapply for the job next year.

Citing Maine laws surrounding personnel matters, the superintendent declined to discuss who lodged the complaint or its nature other than to say it was “very narrow in scope.” When pressed, he would not elaborate other than to say that the subject of the investigation “would suggest it’s very specific” as opposed to an ongoing problem.

But in a statement Wednesday about the investigation, Caulk wrote specifically about racial discrimination.

“I am proud of our record in addressing racial and cultural awareness and sensitivity among staff and students,” he wrote. “We are not perfect, but we do not tolerate discrimination in any form, and we respond firmly when it occurs. Well before the Deering football issue was raised, I began initiatives to provide additional staff training with regard to racial and other forms of bias, and those initiatives will continue and expand. Those efforts will include training on discrimination, harassment and bullying for all coaches and athletic administrators in the Portland schools.”

Reached Tuesday at his home, Riddell declined to comment on his departure.

Caulk said that he learned of the allegation against Riddell on Veterans Day. He said he replied in person to the complainant the following day, notifying the person that the school would investigate the allegation.

The superintendent said such an investigation typically lasts seven to 10 business days in order to allow facts to be collected.

“We made certain not to engage in any rush to judgment or to do anything that was incendiary,” he said.

But before the investigation was completed, Riddell notified the school district that he would not re-apply for the job, and would not coach the Thanksgiving Day game.

“He said he thought the assistant coach could handle the last game,” Caulk said. “To my knowledge it was voluntary. To my knowledge it was not related to this investigation.”

The superintendent said the investigation continued “because we have integrity and because we take all allegations seriously.” That investigation has now concluded, but Caulk would not release the findings.

“We acted on it, we didn’t sweep it under the rug or try to bury it,” he said.

Caulk said he was not aware of any formal complaint filed by the NAACP about Riddell, nor was he contacted about the allegation by the NAACP. But he said he spoke with “NAACP leadership” Tuesday evening, “and we are on the same page with respect to our collective work of ensuring racial equity.”

Rachel Talbot Ross, state director of the Maine NAACP, did not respond to phone calls and emails on Tuesday and Wednesday.

“We have had a very positive relationship with the NAACP for years,” he said. “We’re currently working together with the city and the United Way on racial equity. At Portland Public Schools, and in the city of Portland, … as the most diverse school district in Maine, and the most diverse city in Maine, we hold ourselves up to be leaders in racial equity.”

Riddell had coached the team for just more than a year. In September 2013, former Deering football coach Scott Parsons resigned after he was ejected from a losing game against Massabesic High School, the Forecaster reported.

A guard and linebacker who graduated from Lewiston High School in 1987, Riddell has more than 20 years coaching experience, including with Bonny Eagle High School, the Maine Sabers and the Southern Maine Raging Bulls, the Forecaster reported.

The school board met Tuesday night, including in executive session, but Caulk said Wednesday that neither Riddell’s departure nor the investigation were discussed.