The Huffington Post reported Sunday on the lawsuit, which accuses Justin Cosma, who was with the Jefferson County Sheriff's office at the time, and another officer of using "unreasonable and excessive" physical force against the boy. The accusations came in September 2012, just after Cosma joined the force in Ferguson.
The Huffington Post's Ryan Reilly, a former reporter for TPM, identified Cosma as one of the officers who arrested him and another journalist from the Washington Post last week at a Ferguson McDonald's amid heated protests.
Cosma and the other Jefferson County officer, Richard Carter, approached the boy in June 2010 and asked if he had been playing on nearby highway, according to the lawsuit. When the boy said that he hadn't, the lawsuit claims the officers "became confrontational."
"Unprovoked and without cause, the deputies grabbed [the boy], choked him around the neck and threw him to the ground," the lawsuit reads. It also alleges that the boy, who was shirtless, "suffered bruising, choke marks, scrapes and cuts across his body" and at some point was "hog-tied" by the officers.
Neither a Ferguson police spokesman nor police Chief Thomas Jackson responded to the Huffington Post's requests for comment.
Police officers in St. Louis County have come under increasing scrutiny since protests against law enforcement over the Aug. 9 fatal shooting of an unarmed black teenager by a white Ferguson police officer became heated.
An unnamed officer, believed to be with municipal police, who was recorded approaching a protester with his firearm raised and saying "I will fucking kill you" was removed from duty Wednesday. Then St. Louis County Officer Dan Page, who worked on crowd control at the protests, was suspended Friday after a YouTube video surfaced that showed him disparaging various groups and describing himself as a "killer."