A surveillance video showing a Christmas tree with racist ornaments in the lobby of the Fourth Precinct headquarters is being reviewed by the Minneapolis police internal affairs unit, which looks at misconduct by officers.

The footage, shot by a surveillance camera in the lobby of the North Side police station, was reportedly handed over to internal affairs, at the direction of Chief Medaria Arradondo.

Two officers who put the ornaments on the tree were placed on paid leave last Friday, pending the outcome of the investigation and on Monday Arradondo demoted the police inspector, Aaron Biard, who oversaw the fourth precinct.

"We can't comment on the video, it's with internal affairs," said Assistant Police Chief Michael Kjos, adding that the department would reserve comment until after the investigation is complete. Kjos, who previously served as the Fourth Precinct inspector, has taken over day-to-day oversight of the precinct until a new inspector is appointed.

The tree was decorated with a pack of menthol cigarettes, a can of Steel Reserve malt liquor, a police tape, a bag of Takis and a cup from Popeyes Louisiana Kitchen, viewed as racist stereotypes of blacks, and was roundly denounced by community members and Mayor Jacob Frey who last week called the display "despicable." On Monday, he said he supported Arradondo's decision to demote Biard from inspector to lieutenant.

The two officers who decorated the tree were not identified by police officials but several sources said they are Mark Bohnsack and Brandy Steberg, both 21-year veterans of the department.

Lobby video cameras are present in each of the city's five precinct stations and are recording continuously. The footage is retained for two weeks before it is erased. It would likely show the tree being put up along with the assorted reactions by officers.

"The video goes to the credibility of the department," said Ron Edwards, a longtime Minneapolis civil rights activist, who first revealed the existence of the video on his internet radio program.

He said two black women, including a school board member, were the first ones to raise concerns about the tree.

A online petition calling on Arradondo to fire the two officers had gathered more than 1,600 signatures as of Wednesday, according to a news release.

The tree controversy is the latest in a series of incidents on the city's North Side and is seen as a setback in the department's efforts to mend frayed relationships with black community members.

Staff writer Andy Mannix contributed to this report.