SAN FRANCISCO (CBS SF) — The Department of Public Health in San Francisco on Thursday confirmed that the House of Prime Rib has voluntarily shut down for an investigation into complaints of alleged food borne illness at the popular restaurant.

The city’s Department of Public Health issued a release Thursday stating it “is aware of ongoing online complaints and alleged food borne illness in relation to the House of Prime Rib on 1906 Van Ness Avenue.”

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“The owner agreed to voluntarily close to the public for 24 hours starting today (5/13) so DPH health inspectors can ensure meal preparation and food handling process is being done safely and to code,” the statement read.

The restaurant had been serving take out meals for much of the COVID-19 pandemic, but in March resumed dinner service at the restaurant.

The release said that as of Thursday morning, the SFDPH office has received a total of 22 complaints of illness in connection with the restaurant. So far in the investigation into the possible food-borne illnesses, Department of Public Health officials have interviewed a total of 55 people.

“The epidemiological-based interviews with the complainants include determining common foods consumed, symptoms, time from eating the meal to time when they begin to feel sick, and other potential exposures,” the release stated.

In accordance with the department’s standard protocol, the recent complaints led SFDPH officials to conduct a food-borne illness investigation at the restaurant on Tuesday. That onsite inspection did not suggest any causal links between the observations made and the alleged food borne illnesses.

The restaurant posted about the visit on its Instagram page.

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SFDPH officials said the investigation into the illnesses connected to the restaurants is ongoing and noted the department would track any additional reports of food borne illness.

“We are working closely with the restaurant owner to identify if there are any possible issues at the facility that could result in food borne illnesses,” the statement said.

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The department also noted it is aware of a variety of private online websites sharing food borne illness experiences and complaints, but strongly encouraged who is experiencing any food borne illness symptoms to formally file a report at the San Francisco Department of Public Health website.