A private security guard may have fired at an officer racing to the Colorado school shooting — and even wounded one of the students, according to a local report citing multiple law enforcement sources.

Authorities are investigating shots fired by the unidentified private security officer who was at the STEM School Highlands Ranch when one student was killed and eight others injured on Tuesday, Denver’s 9 News reported.

One of the Douglas County sheriff’s deputies racing to the classroom reported that the security guard had fired as they arrived, according to the report.

“Investigators are also looking at the possibility a bullet from that security officer’s gun may have hit and wounded one of the students injured in the incident — a question that likely will not be answered until ballistics testing is complete,” 9 News insisted.

Douglas County sheriff’s spokeswoman Cocha Heyden declined to comment on 9 News’ report, saying the attack is an ongoing investigation.

Security company owner Grant Whitus, whose guard was at the school, also insisted the claims were “news to me.”

“I know nothing about that because I haven’t interviewed him,” Whitus, a former sheriff’s officer who now owns BOSS High Level Protection, told the station. “Douglas County hasn’t interviewed him yet, so I can’t comment.

“I can’t talk to him until the sheriffs have talked to him.”

Whitus previously told FOX31 that his guard at the school, a former Marine and sheriff’s deputy, had been a hero who saved lives during the attack.

“Our guy was instrumental in taking down one of the shooters and we believed he saved a lot of lives,” he insisted.

“He is so upset about children being hurt, he loves that school, he loves the children there and his heart is breaking he couldn’t do more.

“I assured him there is only so much one person can do.”

Tyler Christensen, an eighth-grader who was near the gunshots, also told FOX31 that the guard was “a hero.”

“He probably saved more lives than he thinks he did,” he insisted.

One student, Kendrick Castillo, 18, died after he and classmates rushed the gunmen during Tuesday’s attack.

Devon Erickson, 18, and Maya McKinney, a 16-year-old female who identifies as a male, both appeared in court Wednesday on suspicion of murder.