Christopher LeDay uploaded the footage of video of the fatal shooting of Alton Sterling by officers in Baton Rouge onto his Facebook page on July 5. He said it had been shared with him by a third party who recorded it.

But in the aftermath of the incident, which sent shockwaves across the country and resulted on in widespread protests, Mr LeDay said he believes his behaviour cost him his job. He said that it led to him being detained the next day when he reported to work for a private security firm at Dobbins Air Reserve Base in Marietta.

Alton Sterling was defenceless on the ground when the white officer pulled out his gun

“I knew I had the platform to share it, to make it go viral and I even requested when I originally posted it that everybody should share this to show some of the heinous crimes that have been committed by law enforcement against black men,” Mr LeDay said last week at a press conference.

He said he was fighting to get his job back and that he was being helped by a lawyer, Tiffany Simmons.

“He's been punished for doing the right thing,” Ms Simmons said according to Fox News. “He’s been punished for being a good Samaritan by showing this video and showing America that we have to look in the mirror and we have to change some things.”

Demonstrators protest the shooting death of Alton Sterling near the headquarters of the Baton Rouge Police Department (Jonathon Bachman/ Reuters ) (Jonathon Bachman/ Reuters)

According to Mr LeDay, a father of three children, military police stopped him when he arrived on base July 6. Dunwoody Police then took him into custody.

A spokesperson for the Dunwoody Police Department said military police ran a search on Mr LeDay as part of the security clearance process. They discovered Mr LeDay was wanted on an old warrant. Officers then arrived on base and transported Mr LeDay to the DeKalb County Jail for “failing to appear on several traffic charges”.

Mr Sterling was shot outside a Baton Rouge convenience store earlier this month after an encounter with two police officers. The officers can be seen in the video kneeling on top of him before shots were fired.