A former US police officer convicted of murder in the death of George Floyd has pleaded not guilty to allegedly violating the civil rights of a teenager in a separate case that involved a restraint similar to the one used on Mr Floyd.

Derek Chauvin was convicted earlier this year on state charges of second-degree unintentional murder, third-degree murder and second-degree manslaughter in Mr Floyd’s 2020 death.

He was sentenced to 22-and-a-half-years. He is also charged in federal court with violating Mr Floyd’s civil rights when he knelt on the black man’s neck for about nine-and-a-half minutes as Mr Floyd was facedown on the pavement, not resisting and pleading for air.

But another indictment against the former Minneapolis police officer alleges that he carried out a similar act against a then-14-year-old boy in 2017.

This indictment alleges Chauvin deprived the teenager, who is black, of his right to be free of unreasonable force when he held the teen by the throat, hit him in the head with a torch and held his knee on the boy’s neck and upper back while he was prone, handcuffed and not resisting.

When Judge Hildy Bowbeer asked how he would plea to the charge, Chauvin replied: “Not guilty, your honour.”

Thursday’s hearing was held via video-link, and Chauvin appeared from the state’s maximum security prison, where he is being held following his murder conviction.

According to a police report from the 2017 encounter, Chauvin wrote that the teen resisted arrest and after the boy was handcuffed, Chauvin “used body weight to pin” him to the floor. The boy was bleeding from the ear and needed two stitches.

That encounter was one of several mentioned in state court filings that prosecutors said showed Chauvin had used neck or head and upper body restraints seven times prior to Mr Floyd’s death dating back to 2014, including four times where state prosecutors said he went too far and held the restraints “beyond the point when such force was needed under the circumstances”.

Chauvin and three other former officers – Thomas Lane, J Kueng and Tou Thao – were arraigned on civil rights violations in Mr Floyd’s death on Tuesday.

All four pleaded not guilty to the charges.

The indictment in the 2017 case was filed the same day as the one for Mr Floyd’s death.

According to the indictment in Mr Floyd’s death, the officers allegedly deprived Mr Floyd of his rights while acting under government authority.

The federal indictment alleges Chauvin violated Mr Floyd’s right to be free from unreasonable seizure and from unreasonable force by a police officer.

Thao and Kueng are charged with violating Mr Floyd’s right to be free from unreasonable seizure by not intervening to stop Chauvin as he knelt on Mr Floyd’s neck.

All four officers are charged with depriving Mr Floyd of his rights when they failed to provide medical care.

Mr Floyd repeatedly said he could not breathe as Chauvin pinned him to the ground.