Derek Chauvin, the former Minneapolis police officer charged with murdering George Floyd, has been released from prison.

According to court documents, Chauvin posted a $US1 million ($A1.4 million) bond on Wednesday (local time) and was released from the state’s correctional facility in Oak Park Heights, where he had been detained.

Mr Floyd, an African American man in handcuffs, died on May 25 after Chauvin, who is white, pressed his knee against Mr Floyd’s neck for several minutes as Mr Floyd said he couldn’t breathe.

Mr Floyd’s death was captured in widely seen bystander video that set off protests around the world over police brutality and racism. Chauvin and three other officers were fired.

Chauvin is charged with second-degree murder, third-degree murder and manslaughter; Thomas Lane, J. Kueng and Tou Thao are charged with aiding and abetting both second-degree murder and manslaughter.

The manner of Mr Floyd’s death spurred Democrats to propose a sweeping overhaul of police oversight and procedures by introducing the Justice in Policing Act.

It was not immediately clear where Chauvin got the money to pay his bond. In Minnesota, someone who posts bond must pay 10 per cent, in this case $US100,000 ($A140,111), to the bond company and have collateral, such as a house, to back the full amount.

A message left with the company that posted the bond, Allegheny Casualty Company, was not immediately returned.

The Minnesota Police and Peace Officers Association, which has a legal defence fund, did not provide any money for bail, a spokeswoman said.

A message left with the union representing Minneapolis police officers was not returned.

The website GiveSendGo.com, which says it is a free Christian crowdfunding site, has a Derek Chauvin Bail Fund that says it was created by his family.

According to the site, as of midday Wednesday that fund raised $US4198 ($A5882) of its $US125,000 ($A175,139) goal, with donations from more than 35 people.

Under the conditions of his release, Chauvin must attend all court appearances, cannot have any direct or indirect contact – including social media contact – with any members of Floyd’s family, cannot work in law enforcement or security, and must not possess any firearms ammunition.

His lawyer had no comment on Wednesday.

Chauvin’s wife, Kellie Chauvin, filed for divorce shortly after Mr Floyd’s death. The records in that case have since been sealed.

In July, the Chauvins were charged with multiple felony counts of tax evasion for allegedly failing to report income from various jobs.

The other three officers charged in Floyd’s death had previously posted bond amounts of $US750,000 ($A1.1 million) and have been free pending trial.

All four men are scheduled to face trial together in March, but the judge is weighing a request to have them tried separately.

-with agencies