The raid on the Grace Road Church premises at Navua on Tuesday was a collaboration between the Korean and Fijian police and immigration authorities.
The Director of Immigration Nemani Vuniwaqa said three senior members of the church had been detained over allegations concerning 400 church members in Fiji.
The church's founder Shin Ok-ju was arrested in Seoul last month and charged with enslaving followers in Fiji.
Mr Vuniwaqa said Grace Road Church executives were working with Immigration to locate the other three suspects wanted in connection to the case.
