They've launched controversial forays into election campaigns in Australia, New Zealand the US. Now the Exclusive Brethren are drawing more unwanted headlines, this time accused of trawling for dirt on the sex life of the NZ Prime Minister's husband. Politics may seem an odd game for a fundamentalist church that prefers a low profile and forbids its flock from voting. But paradoxes abound in the Exclusive Brethren. They're a relatively small outfit that owns considerable property assets. They ban mod cons like the Internet, TVs and mobile phones but run a profitable office equipment business. Crucially, they pride themselves as a bastion of family values. Tragically, however, family fracture and heartbreak are also part of the Exclusive Brethren story. The Brethren refuse to socialise with any outsiders, even close relatives, purposefully separating themselves from a world they see as morally corrupt. Infractions of internal rules -- real or perceived -- can lead to excommunication, or being "withdrawn from", and complete, permanent isolation from loved ones. 'I had a knock at the door saying that we've excommunicated you and you're not to sleep with your wife tonight,' says one former senior Brethren member who fell out with the then leader more than 20 years ago and hasn't seen his wife or children since. His sons wrote to tell him they don't want to see him because he's 'not right and withdrawn from and out of fellowship'. He treasures these painful letters from his boys; he loves to look at their handwriting. A woman who left the Brethren voluntarily tells how they viewed her as dead -- a 'dead separation'. She too was cut off from her own family until her father was excommunicated. He never saw his wife again and died lonely, aged nearly 90. 'Everything I loved was stripped from me,' says a man describing losing his wife and children, his home and his business. 'These people claim to represent Christianity in its purest form but you look at the history stretching back 30 or 40 years and it's just carnage -- broken families, broken lives.'These are not isolated cases. Insiders turned outcasts speak candidly and emotionally to Four Corners about the Exclusive Brethren practice of family separation.