WASHINGTON (AFP) - The parents of a United States teenager are suing after their son was shot dead during a police traffic stop, media reports said, as video of the deadly encounter emerged.

The case comes amid a national debate on the use of force by police in the United States, with white officers often accused of racism. In this case, however, both the officer and the teenager were white.

Bodycam footage of the February incident in Michigan shows 17-year-old Deven Guilford repeatedly questioning and defying demands by Eaton County Sheriff's Sergeant Jonathan Frost to hand over his licence, registration and proof of insurance.

Sgt Frost, who reportedly pulled Guilford over for flashing him with his high beams, then orders the teenager - who was en route to see his girlfriend on a Saturday evening - out of the car and the situation quickly escalates.

"Down on the ground, now!" yells the officer who then kicks Guilford's cellphone away before tasing him and subsequently shooting him seven times in a confrontation that was not caught on camera in its entirety.

"I don't have a weapon," Guilford is heard saying on the footage posted on the website of NBC News .

Guilford's parents filed a federal lawsuit this week against both Sgt Frost and Michigan's Eaton County, four months after prosecutors decided not to charge the officer, reports said Friday.

Sgt Frost has said Guilford attacked him before he shot the teenager, according to NBC. And bodycam footage of Sgt Frost purportedly taken after the incident aired by CNN shows his face bloodied.

The wrongful death and violation of civil rights lawsuit, published by the Detroit Free Press, claims that Sgt Frost had no legal cause to stop Guilford and that Sgt Frost "unreasonably treated Guilford as if he were a dangerous felon".

The lawsuit also says that Sgt Frost's car had "improperly bright or misaimed, headlights" and that at least three vehicles, including Guilford's, flashed their headlights at him in an apparent attempt to get him to dim them because they "projected glaring oncoming rays into the eyes of oncoming drivers".

It also says Guilford was driving his girlfriend's car at the time of the incident - the evening of Feb 28 - and was on his way to see her after playing basketball at his church with his brother.