A Teaching Council spokeswoman told the Herald: "The Teaching Council has received a notification relating to [Faithful Pilgrim] and that notification is currently under investigation by the [Complaints Assessment Committee]."
It's alleged Pilgrim was aware of the claims against Standfast when they first surfaced but still allowed him to teach.
In the leavers statement, it said it was unlikely the people inside Gloriavale will know that Pilgrim was under investigation.
They said Pilgrim had recently stood down from the role on advice from his lawyer.
Manager of the Gloriavale Leavers' Support Trust Liz Gregory said the trust had become frustrated when attempts to alert authorities to the danger children were in, were not taken seriously and investigated immediately.
As a result she made a complaint directly to the Teaching Council on behalf of a number of leavers who expressed concern.
Ex-member Virginia Courage said she was aware of school teachers who were known to have touched young girls inappropriately.
"It was just sort of common knowledge. I remember the girls talking about it, but not knowing what to do.
"There was never anything said to the children that if something was happening to them, here is what you should do."
It's understood Pilgrim has spent more than 40 years at the commune, much of this time as principal of the school, the leavers trust said.
In 2012, when Standfast was still a teacher at the West Coast community, he assaulted a 9-year-old girl from his class. During his sentencing, Judge Raoul Neave noted that she was "something of a favourite" for the 68-year-old man.