The April 4 inspection of the organization’s community center was a continuation of the Russian authorities' review of nongovernmental organizations around the country.
Russian officials from various agencies have been collecting registration and finance documents from hundreds of NGOs since mid-March.
The authorities say they are checking if the NGOs are in compliance with new laws on foreign financing.
The director of the Caritas community center in St. Petersburg, Natalya Pevtsova, said members of the city's education committee and officials from antiextremism, antiterrorism, and tax offices also took part in the inspection.
She said the visit shocked her organization's workers, volunteers, and clients.
Russian authorities are expected to report on April 8 on the results of the Caritas inspection.