A Florida police officer who suffered post-traumatic stress after witnessing the horror of the Pulse nightclub shooting has been abruptly fired, just months before he would have secured a pension bonus for 10 years’ service.

Omar Delgado was one of the first officers to respond to the June 2016 massacre and helped wounded survivors to safety from inside the Orlando nightclub as the gunman, Omar Mateen, continued a killing spree that claimed 49 lives.

He suffered significant psychological trauma from the incident, then America’s deadliest mass shooting, and has been confined to desk duty and light administrative tasks since returning to work eight months ago.

Now, in a decision that Pulse co-founder Ron Legler has branded an injustice, the Eatonville police department is terminating Delgado’s contract from the end of this year. It means he will fall six months short of the 10 years’ service required for an annual pension of 64% of his $38,500 salary for life and, as an employee for less than a decade, he will receive only 42%.

Eddie Cole, the Eatonville mayor, was unavailable for comment on Thursday, but at a town council meeting on Tuesday night said he could not discuss the reason for Delgado’s termination because of employee privacy.

“This town, as well as me, cares about people. But some pictures are bigger than we all know,” the Orlando Sentinel reported Cole as saying.

However, Delgado, 45, claims a superior officer told him the department needed an officer on patrol rather than at a desk, and that the PTSD for which he is still receiving counselling was a factor in the decision.

“It’s a small town and we’re like a family,” Delgado told USA Today. “You don’t just throw a family member to the street. They’re acting like a Fortune 500 company and saying since you can’t do your job we’re going to replace you. Even if the world saw me as a hero, that was yesterday.”

Legler, who founded the Pulse club in 2004 with his friend Barbara Poma after her brother’s death from HIV, said he would fight to have the decision overturned.

“Know that you have a community of passionate people that will not rest until this wrong is made right,” Legler, president of Baltimore’s France-Merrick performing arts centre, wrote in a post on a GoFundMe account set up by a friend of Delgado to help his family with medical bills and the upcoming salary loss.

“We will not let this injustice stand. We will all work as hard for you as you did for us that horrible night.”

One of the injured victims that Delgado saved also came to his defence. Angel Colon, who was shot six times by Mateen and who became a close friend and supporter of the officer who helped him escape in the months afterwards, told WFTV: “For them to just do what they’re doing to him in front of my face is a slap to my face as well.

“He did his job that night … so they should have his back 100% totally and just be there for whatever he needs.”