A former Minneapolis police officer was sentenced Thursday to two and a half years in federal prison for his role in the killing of African-American George Floyd.

Thomas Lane was convicted in February of violating the civil rights of Floyd, the man whose May 2020 murder by senior officer Derek Chauvin sparked protests across America.

Lane, alongside ex-colleagues Tou Thao and J. Alexander Kueng, was found guilty of showing "deliberate indifference" to Floyd's medical needs.

Chauvin, who kneeled on the neck of a handcuffed Floyd for nearly 10 minutes until he passed out and died, was convicted of murder last year and is serving 22 years in prison.

Federal prosecutors had called for US judge Paul Magnuson to sentence Lane, who is white, to more than five years in prison.

His lawyers had asked for a much lighter sentence of just over two years, on the grounds that Lane had suggested placing Floyd on his side and tried to resuscitate him.

The judge went with 30 months, with two years of supervised release.

"It's terrible," one of George Floyd's brothers, Philonise Floyd, told television cameras outside court.

"This whole criminal system needs to be torn down and rebuilt," he added.

Lane, 39, was new to the job when he and fellow rookie cop Kueng apprehended Floyd after a shopkeeper accused him of using a counterfeit $20 bill in his store.

As they struggled to get the heavyset Floyd in their vehicle, the pair were joined by two experienced officers, Chauvin and Thao.

Thao and Kueng were also convicted of failing to intervene to stop the use of "unreasonable force" against Floyd by Chauvin.

Lane, who is white, did not face that second charge. Video of the arrest shows that on two occasions, Lane suggested that Floyd be rolled over on his side.

In May, Lane pleaded guilty to separate state charges of aiding and abetting second-degree manslaughter, under a plea agreement that will see him spend three years in jail.

That term will run concurrently with the sentence he received on Thursday.

Floyd's death, which was filmed by a bystander in a video that went viral, sparked months of protests against racial injustice and police brutality in the United States and around the world.