Federal authorities are investigating reports of a man allegedly identifying himself as an immigration agent and questioning Gwinnett County residents, Channel 2 Action News reported.

The incidents occurred in an immigrant community with a large Hispanic population along Old Norcross Tucker Road in the Norcross area. Some residents say an individual has been questioning people without cause and threatening them with deportation.

According to an article in the Mundo Hispanico metro Atlanta Spanish-language newspaper, the man shows people a business card identifying himself as a member of the Fugitive Operations Unit of Immigration and Customs Enforcement of the U.S. Department of Homeland Security.

The alleged incidents happened the last two weeks of February.

Management of an apartment complex in the area contacted Gwinnett County police and sent warning letters to tenants about an individual posing as a police officer or immigration agent. The letter advised that they did not have to open a door to a stranger and should use caution.

“I’m really upset, flabbergasted,” Teodoro Maus, of the Georgia Latino Alliance for Human Rights, said of the reports. “What we tell [residents] is, don’t show anything unless they show you a warrant, unless they show you a reason for why they’re knocking on your door.”

Immigrations and Custom Enforcement told Channel 2 in a written statement, “The ICE Office of Professional Responsibility is conducting an internal investigation into allegations of improper conduct by a possible employee of the Atlanta field office and/or an imposter posing as a federal officer.”

The statement says the case is ongoing, so no other information will be released.