TFI is running "services" in the community

I live in a developing country and TFI is active here. I am pretty sure that a TFI member has started dance classes in the broader community (they also do birthday parties, christmas caroling at hotels, etc. to raise money). Everyone is sending their kids to ballet. I have told some of the other parents my suspicion about the people running the class but nobody seems to be bothered and I have a difficult time convincing anyone that there's anything to worry about because the people are "so nice". Can anyone guide me in 1. how to verify if these people are part of TFI and 2. what we might need to worry about if sending children to these classes. Thanks, kwd