A D.C. police officer who admitted to wearing a T-shirt in public that was printed with what authorities said were inappropriate and possibly offensive images has been disciplined, according to Peter Newsham, the District's police chief.

Newsham said two supervisors also were disciplined for knowing about the shirts but failing to take action. The shirts, which were printed with the name of a police unit, had depictions of the Grim Reaper and a pre-Christian style of cross that an advocacy group said has been used as a white-supremacist symbol.

Newsham declined to describe the type of discipline but said none of the officers had been fired. He said as many as a dozen other officers were suspected of buying the shirts, but all denied wearing them. The chief said it could not be proved that the cross was intended to be a white-supremacist symbol, citing an Anti-Defamation League report that said the symbol may have been added unintentionally because it is part of the font used in the lettering on the shirt.

One officer was spotted earlier this year wearing the shirt over his uniform in D.C. Superior Court; some officers wear shirts over their uniforms when off-duty to avoid being recognized as police. Officials have said this officer was considered on-duty while in the courthouse waiting for a hearing.

It could not be determined if the officer in court was the same officer who was disciplined. The officer wearing the shirt had been photographed by a member of Law for Black Lives, a group of legal professionals affiliated with Black Lives Matter. The officer was put on desk duty when a complaint was made in March. He was not identified by police but was named by advocates concerned about the shirts.

Eugene Puryear, an organizer with a group called Stop Police Terror Project D.C., which filed the complaint, said he is disappointed that more officers were not sanctioned but pleased that supervisors were disciplined.

"It reinforces the point that we made all along, that obviously there is a culture that tolerates this kind of thing," Puryear said. "It vindicates some of the criticism we were making that we think there were a lot more people who had the shirts and who deserve punishment."

The T-shirts refer to the 7th District, which includes some of the city's most violent areas: Anacostia, Barry Farm, Naylor Gardens and Washington Highlands.

The shirts have the Grim Reaper as the centerpiece, holding what appears to be a rifle with the District of Columbia flag attached. At the top is the word "powershift," referring to officers assigned to a special unit that focuses on tough crime areas. The cross is embedded in the O in "powershift." The advocacy group says it's the same type of cross used in the logo for the neo-Nazi website Stormfront.

The Anti-Defamation League lists a variant of that cross as a commonly used white-supremacist symbol but said the intent of the shirt's designer was unclear. A research fellow at the center said in August that the font used in the lettering on the shirt may be responsible for the cross appearing in the O, rather than it being a deliberate attempt to copy the neo-Nazi symbol.

Newsham, who earlier this year termed the shirt "disturbing and disgraceful," noted the Anti-Defamation League's stance that there may have been no racist intent behind the shirt. He said the department was "unable to prove it was white supremacist in any way."

Regardless, Newsham said, the shirt was "inappropriate." The department's rules prohibit officers from wearing clothing that contains language "of a social, economic or political nature that might be considered as an advocacy statement, or which might create controversy."