The 13-year tenure of head football coach Steve DeVoursney, who led Griffin High School to the Class AAAA championship last season, ended Thursday when the Griffin-Spalding County Schools board of education voted 5-0 to accept the resignation of DeVoursney and his wife, Jessica, a science teacher at the school.

The school board’s decision came in the wake of a five-month investigation into allegations of illegal recruiting of athletes and improper academic assistance, according to the final report obtained through an Open Records request by The Atlanta Journal-Constitution.

DeVoursney and his wife, who sent letters of resignation Tuesday, denied wrongdoing. They were placed on administrative leave by the board and will be paid through the end of the school year, according to a school-board official.

Curtis Jones, superintendent of Griffin-Spalding schools, said that a report will be filed with the Georgia High School Association, but that Griffin’s state championship would not be jeopardized because the 2013-14 school year was not in question.

The probe, requested by the school board and conducted by an independent investigator, looked into allegations that Jessica DeVoursney did school work for football players to keep them eligible while serving in the role of academic adviser to athletes.

The investigator’s report made no conclusions about misconduct. The report released by the school board outlined several allegations and complaints from interviews by the investigator and human resources of more than 20 current or former school-system employees, mostly Griffin High faculty members.

The events that prompted the investigation began in September 2013, when Griffin principal Keith Simmons questioned the legality of the transfer of an athlete from his school to county-rival Spalding High. The schools are located five miles apart.

Simmons wrote a letter to the GHSA that asserted that the transfer student from Griffin did not live legally in the Spalding district, according to the report. Simmons speculated in the letter that Spalding football coach Nick Davis illegally recruited the athlete.

In October, Spalding principal Derrell Jeffcoat responded by asking for an investigation of his own by the school board after a transfer student from Griffin was found to be academically ineligible for sports. In a letter to the board of education on Oct. 28, Jeffcoat questioned the integrity of a “course recovery’’ program at Griffin that the student completed in 2011.

“Spalding High School believes the awarding of an 18-week semester credit in a one-day period surpasses any complaints hence filed between the two schools,’’ Jeffcoat wrote.

On Nov. 7, the school board hired an investigator, Richard Hyde. His report and other human-resources interviews quoted several Griffin faculty members as expressing suspicion of cheating or misconduct in Griffin’s online course-recovery program, which gives students the opportunity to retake courses they previously failed to receive credits toward graduation.

The transfer student, who was not identified, also was interviewed. He accused Jessica DeVoursney and an assistant football coach of giving him answers to tests. Jessica DeVoursney denied those allegations in the report and indicated the student’s motives were spiteful, “because he hates my husband.’’

Griffin’s principal, Simmons, defended Jessica DeVoursney during questioning and said he was unaware that other teachers called her or the program into question. “I can’t fathom her doing it. I don’t see him (Steve DeVoursney) putting her in that position,’’ he said.

Simmons also defended Steve DeVoursney on allegations of recruiting and improper help to student-athletes. “He can act selfishly or immaturely, yes, but not risk his livelihood. He certainly complains about his salary. It wouldn’t make sense to jeopardize it.’’

Jones, the superintendent, said the school board had reported its findings to the Professional Standards Commission that monitors teacher ethics. Jones said he asked its teaching-and-learning department to review protocols regarding academic integrity.

“It is always hurtful and upsetting to hear allegations about our school-system employees,’’ Jones said. “However, we all have an ethical and moral obligation to our students and community to investigate complaints to ensure that Griffin-Spalding students receive the best education possible.’’