The Exclusive Brethren Church has been using the discredited private investigators Thompson and Clark to spy on former members.
A two-year investigation for RNZ has found the church, described as cult-like by some, is a major and secret client of the controversial private investigators.
Investigative reporter Nicky Hager says the discredited company has dossiers on at least 20 former members of the Exclusive Brethren, based on street surveillance, monitoring of social media, checks in public records and information supplied by church leaders.
Thompson and Clark was the subject of an enquiry by the State Services Commission after it was caught spying on Canterbury quake claimants and state abuse complainants.
Nicky Hagar says these former exclusive brethren members have committed no crime against the church, which now calls itself the Plymouth Brethren.
Doug Watt of the Plymouth Brethren Church says just like any church, we are sad if someone leaves us, but wish them all of the best in their lives, and of course, hope that one day they will change their mind. In a written statement Watt says
"What our Church or leadership does not do is launch secretive, clandestine, overnight operations with hired private investigators!"
And he goes on to say "While we cannot comment on the actions of every individual within our Church, it is certainly true to say that the Church leadership has absolutely no knowledge or involvement in the matters you have described.
Thompson and Clark have also responded to our story saying In a written statement Gavin Clark says "Thompson & Clark has always strived to operate within the law and the rules and regulations of our industry.
He says this was confirmed by the Private Security Personnel Licensing Authority and the Police following the State Services Commission inquiry.
Clark says the Police advised Thompson & Clark that it found no evidence of any criminal offending by either the company or its contractor regarding work done for Southern Response.
While, the licensing authority ruled that Thompson & Clark did not breach the Act or the Code of Conduct for private investigators and is not guilty of misconduct or gross negligence.