CHICAGO (CBS) — Despite indoor dining at restaurants being prohibited for more than a month, Ald. Tom Tunney (44th) on Monday called it an “error in judgment” when his Ann Sather Restaurants allowed regular customers to eat inside in recent days.

“On a sporadic basis, we have allowed a very limited number of our regular diners to eat inside the restaurant while observing social distancing and mask-wearing rules. This was error in judgement and won’t happen again,” Tunney said in a statement.

READ MORE: Neighbors Alarmed After Rash Of Robberies In Lakeview; Police Patrols Increased Along Southport Avenue

The alderman did not specify how many customers he has allowed to dine indoors or how often.

A spokesman for the city’s Department of Business Affairs and Consumer Protection said the city is investigating.

“Throughout the COVID-19 crisis, BACP has worked hard to hold all businesses accountable to the COVID-19 regulations designed to keep our community safe. While our focus has always been on education, we have not hesitated to take appropriate enforcement action when necessary. This matter is under investigation and the department will handle the investigation in the same manner as we have handled thousands of investigations throughout the pandemic,” BACP spokesman Isaac Reichman said in an email.

In a statement, Mayor Lori Lightfoot’s office said the city’s “COVID-19 guidelines and restrictions apply to every single individual and establishment in Chicago so that we can further ensure the health and safety of our residents.

“Any business found in violation of these guidelines has been and will be held fully accountable. No exceptions,” the mayor’s office added.

Sources said the city had not received any complaints about COVID-related violations at any Ann Sather restaurants before Monday.

At least one viewer contacted CBS 2 over the weekend, saying they had been allowed to dine inside at the Ann Sather Restaurant on Belmont Avenue after calling ahead to ask about outdoor seating. The viewer claimed tables indoors were not adequately spread out, and at least one table had a party larger than six people, the per-table limit for outdoor dining.

“They just took us to a back room, and the front rooms were closed off for seating. We went into the back room and there was a table of eight or 10 people and three or four together tables not spaced out, and they just sat us down like we were regular people,” Melissa Smith told CB2 Investigator Megan Hickey.

She said she felt uncomfortable. So she and her boyfriend got up and left before ordering. She called 311 to report it. She also said she was not a regular customer, though she had eaten there before.

READ MORE: Some Parents Not Pleased As Kids Are Required To Wear Masks During Outdoor Recess At Jonathan Burr Elementary School In Wicker Park

Tunney declined CBS 2’s request for an interview but spoke with us less than two weeks ago, saying his restaurant was “heeding the advice of our health department and our mayor” when it came to Thanksgiving meal preps. He also acknowledged they were really struggling.

“Our business has been cut in half,” he said at the time.

Smith said she understands the motivation for a businesses like these that are hurting — through no fault of their own, but says there are better ways to show support.

“We try to eat outdoors in December in Chicago when we can and take out, and that’s why its hard to support a restaurant that’s ignoring all that,” she said.

Gov. JB Pritzker said he agreed that it was a “tremendous” lapse in judgment by Tunney.

“I also will say that elected officials should be setting an example, not creating the example that people may follow that will spread coronavirus. We have mitigations in place for a reason. We have asked everybody to follow them, and frankly most restaurants and bars have followed them,” he said.

Ann Sather is still open for carry out and delivery.

Indoor dining and bar service has been prohibited in Chicago since Oct. 30, amid a new surge in COVID-19 cases. City and state orders allow restaurants only to serve customers outdoors, or through drive-through, carry-out, pickup, or delivery.

Shortly after Pritzker’s office announced the indoor dining ban in Chicago in late October, Lightfoot said she was “very concerned” about the impact it would have on Chicago’s small businesses, and suggested she would try to convince the governor to change his order. But after an hourlong meeting with Pritzker, the mayor later said she was “not asking for any special treatment” and would enforce the indoor dining ban.

Between Oct. 30 and Nov. 30, the city has conducted 877 investigations of bars, restaurants, and other businesses for allowing indoor drinking or dining, and has issued 20 citations and 54 “notices to correct.” The city also has issued one-day closure orders to nine businesses, four of which were also ordered to stay closed until the city approved a reopening plan, due to particularly egregious violations.

MORE NEWS: North Halsted Street Mainstay Yoshi's Café Set To Close This Month After Nearly 40 Years In Business

Also From CBS Chicago:

Megan Hickey