The suspected thefts, which total more than $3.8 million, have been ongoing for six years, prosecutors say, The New York Times reports.
The man, who worked as a baker in the church's café and sat on its board, is alleged to have used his position to open accounts in the church's name, which he then controlled. According to the investigation, he is alleged to have used the money for, among other things, food, bills and failed business projects. He denies the allegations.
The church says it has stable finances and that all operations are continuing as planned.
"I can't say much because there is a legal process underway that must be allowed to run its course. But we take the events very seriously and want to get to the bottom of what happened. We continue to cooperate with the authorities," vicar Fredrik Ollila wrote in a press release.
