A sixth Memphis officer has been fired after an internal police investigation showed he violated multiple department policies in the violent arrest of Tyre Nichols, officials said.

Preston Hemphill had previously been suspended as he was investigated for his role in the January 7 arrest of Mr Nichols, who died three days later.

Five Memphis officers have already been fired and charged with second-degree murder in Mr Nichols’ death.

Mr Hemphill was the third officer at a traffic stop that preceded the violent arrest but was not where Mr Nichols was beaten.

On body camera footage from the initial stop, Mr Hemphill is heard saying that he stunned Mr Nichols and declaring: “I hope they stomp his ass.”

Also on Friday, a Tennessee board suspended the emergency medical technician licences of two former Memphis Fire Department employees for failing to render critical care.

The suspensions of EMT Robert Long and advanced EMT JaMichael Sandridge build on efforts by authorities to hold officers and other first responders accountable for the violence against Mr Nichols, who was black.

Six black officers have been fired and charged with second-degree murder and other charges. One other officer has been suspended. The Justice Department has opened a civil rights probe into the attack that was captured on video.

Three fire department employees were fired after Mr Nichols died. Former fire department Lt Michelle Whitaker was the third employee let go, but her licence was not considered for suspension on Friday.

The department has said she remained in the engine with the driver during the response to Mr Nichols’ beating on January 7. He died on January 10.

Emergency Medical Services Board member Jeff Beaman said during Friday’s emergency meeting that there may have been other licensed personnel on scene — including a supervisor — who could have prevented the situation that led to the death of Mr Nichols.

Mr Nichols was beaten after police stopped him for what they said was a traffic violation.

Video released after pressure from Mr Nichols’ family shows officers holding him down and repeatedly punching, kicking and striking him with a baton as he screamed for his mother.

Six of the officers involved were part of the so-called Scorpion unit, which targeted violent criminals in high-crime areas.

Police Chief Cerelyn “CJ” Davis said after the video’s release that the unit has been disbanded.

The killing led to renewed public discussion of how police forces can treat black citizens with excessive violence, regardless of the race of both the police officers and those being policed.

At Mr Nichols’ funeral on Wednesday, calls for reform and justice were interwoven with grief over the loss of a man remembered as a son, a sibling, a father and a passionate photographer and skateboarder.