The Memphis Police Department on Friday said it had fired a sixth officer involved in the arrest of Tyre Nichols, the 29-year-old African American whose fatal beating shocked the nation.

Preston Hemphill, who had been in the southern US city's police force since 2018, "violated multiple departmental policies," including on "personal conduct," "truthfulness" and regulations on Taser gun use, the department said in a statement.

Five other officers had already been fired and charged with murder over Nichols's death.

Hemphill, a white man, had been suspended since the beginning of the department's investigation, but that was not made public until Monday.

Nichols was arrested by members of a special police unit called Scorpion on January 7 for what police said was a traffic violation.

Footage of his vicious beating, recorded on body cameras and security cameras, triggered national outrage when it was made public last week.

Police video showed Hemphill at the initial traffic stop when officers attempted to detain Nichols, but he was not among the officers who chased Nichols down and beat him.

A funeral for Nichols was held on Wednesday, with Vice President Kamala Harris in attendance.