Former Minneapolis police officer Derek Chauvin, convicted last year of murdering George Floyd, has been sentenced to 20 years and five months in prison on separate federal charges of violating Mr Floyd’s civil rights during the deadly May 2020 arrest.

Chauvin, who pleaded guilty to the federal charges in December, is already serving a sentence of 22 and a half years in a Minnesota prison for Mr Floyd’s murder after a trial in state court last year.

The federal sentence will run concurrently, local news channel KSTP-TV reports.

US District Judge Paul Magnuson announced the sentence in St Paul, Minnesota, on Friday (Australian time).

Chauvin’s decision to plead guilty averted a second criminal trial for him.

The 46-year-old Chauvin, who is white, admitted he violated Mr Floyd’s right not to face “unreasonable seizure” by kneeling on the handcuffed black man’s neck for more than nine minutes in a murder captured on mobile phone video.

Mr Floyd’s death led to protests in many cities in the US and around the world against police brutality and racism.

In his state trial last year, Chuavin was convicted of intentional second-degree murder, third-degree murder and second-degree manslaughter.

People sentenced to prison for felonies in Minnesota are usually released on parole after serving two-thirds of their sentence.

Chauvin’s guilty plea to the civil rights charges came as part of an agreement with prosecutors under which he would be due to face between 20 and 25 years in federal prison.

In that agreement, he admitted for the first time that he was to blame for Floyd’s death.

Federal prosecutors had asked Judge Magnuson to sentence Chauvin to 25 years.

Mr Floyd could be seen in videos pleading for his life before falling still on the road beneath Chauvin’s knee.

Chauvin was helping three fellow officers to arrest Mr Floyd in May 2020 on suspicion that Mr Floyd had used a fake $US20 banknote when buying cigarettes.

Those three – Tou Thao, J Alexander Keung and Thomas Lane – were found guilty in federal court in February of violating Mr Floyd’s rights.

They have not yet been given a sentencing date.

A medical examiner determined that the police restraint stopped Mr Floyd from being able to breathe.