Zion Pilgrim, a longtime trustee of the religious group, penned a letter to leader Howard Temple raising his concerns of "sexual immorality" and a "pre-eminence of sin" in the community, Newshub reported.
"We do have some serious concerns about some of the fundamental ways of thinking and behaving here that we believe are not in line with God's word," the letter read.
"There is also some very concerning fruit that cannot be ignored; the sexual immorality issues and the pre-eminence of sin, pride, lack of love."
Pilgrim was critical of the fact that church members often had to agree with what the leaders said, even if it was wrong, and a lack of accountability among leadership.
Newshub reported Pilgrim was given an ultimatum by church leaders: to either support leaders or leave the community.
Pilgrim consequently left Gloriavale and moved to south Canterbury with his wife and 12 children.
Last month, former members of the Christian community said those that were still there didn't have the freedom to vote for who they wanted to in the general election.
The issue was outlined in a list of concerns to The Charities Services by The Gloriavale Leavers Support Trust, with ex-members saying those still inside didn't have free access to the internet or news sources and were told as a collective who to vote for.
James Harrison, who left Gloriavale in 2015, told RNZ members didn't have free access to the internet or news sources.
"The group of people who go into town for the weekly shopping trip would bring back old newspapers and then some stories would be cut out and be put on the pinboard but everything we would see is censored."
Another former member, who did not want to be named, said Gloriavale leaders would choose which politicians would come and talk to the community before an election.
"They would talk about their policies and what they would do for us then when they left there would be a discussion, but it was usually only a couple of the leaders who would talk," she said.
The former member said they were even shown voting papers before they went to the polling booth.
"They would say tick here and here just in case we forgot the name or what to do when we got there," she said.
"I remember being in line waiting to vote and someone in front turned around and asked which person we were voting for."
The Gloriavale Leavers Support Trust has given a list of concerns to The Charities Services, who they want to reinvestigate the community.
