A millionaire dairy farming couple is trying to prove their son is mentally unwell after he left their church and raised concerns about the family business.

Erin Bay says he has been cast out by his parents Stuart and Beth Bay after he left the Open Brethren church to become a Catholic.

He says his parents approached an Auckland psychiatrist without his knowledge on October 26, claiming their son was spiralling out of control.

CHRIS SKELTON / FAIRFAX NZ Bay says he made huge personal sacrifice to stay working on his family's dairy farm.

The psychiatrist provided them with a letter to Bay urging him to seek medical attention, and even though he hadn't seen Bay for seven years, suggested he was suffering from bipolar disorder.

"Your family are currently very concerned about you, and from what I have understood, it is highly likely that you are again having another active episode of bipolar disorder," the psychiatrist wrote in the letter.

The letter did not detail the concerns expressed to him by Bay's parents. It was addressed to Bay care of his parents' address. The psychiatrist made it clear his opinion was based on Bay's clinical presentation and history in 2008 and 2009, as well as what he had been told by Bay's parents.

CHRIS SKELTON / FAIRFAX NZ Bay is now living in an unfurnished flat.

The letter urged Bay to seek medical advice and recommended he see a psychiatrist for an evaluation and recommendations.

Bay's parents then used the letter to threaten to have him sectioned under the Mental Health Act.

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The family became involved in a messy dispute after Bay announced he was leaving their Open Brethren church earlier in 2016.

Bay's family is closely involved with the church; his father Stuart Bay is a trustee of the Brethren charity Trinity Lands, which manages more than $200m in assets in Waikato.

Bay estimates his family's personal holdings are worth around $30m, over and above assets owned by and managed on behalf of the church.



Bay worked as general manager on the family's dairy farm, but said he resigned after conditions became intolerable.

Bay, who said he had sacrificed a lot to stay and work on the family farm, said he was astounded to learn his parents had used the psychiatrist seven years after he had last seen him.

Bay first learnt of the visit after emailing his father on October 28 with concerns about the family business.

"Within 40 minutes (they) replied with (the psychiatrist's) letter, which he'd had up his sleeve for two days," he said.

Bay's parents demanded their son seek urgent medical treatment.

"If visits are not done by next Wed 2 Nov we will seek the support of the Waikato Mental Health Crisis Team who can act under Section 8 of the Mental Health Act," they wrote.

Bay temporarily left Waikato out of fear his parents would follow through on the threat.

He acted on the psychiatrist's recommendation and now sees Auckland psychotherapist Colleen Emmens, who noted in a report after six sessions that Bay did not appear to suffer from bipolar disorder.

"He remained in the moment, clear and articulate, and [was able to] reflect and respond appropriately," she wrote.

Emmens wasn't surprised Bay was upset.

"He'd just escaped, and was full of paranoid confusion, and was very distressed," she said.

"But it would have been more concerning if he hadn't displayed those symptoms given the circumstances."

Emmens said in her view the psychiatrist's letter made no sense given he hadn't seen Bay since 2009.

Bay fears his parents are now using the letter to suggest to friends and colleagues that he is unwell.

"Extended family were contacting me saying it was appalling I was bringing the Bay name into disrepute," he said.

"I go to approach people from the church in the street, and they'll start walking away from me."

Bay now lives apart from his wife and children in a house with no furniture while he tries to sort things out.

"The worst thing for me is that my children might grow up thinking that their father was something he wasn't," he said.

Stuart Bay declined to comment.

Through his lawyer, the psychiatrist also declined to comment.

WHO ARE THE OPEN BRETHREN?

The Open Brethren are not as widely known as the Exclusive Brethren, but have their roots in the same movement.

The two branches split in 1848 following a disagreement over whether church leadership should be centralised from London.

Open Brethren have in recent years tried to distance themselves from being associated with the controversial practices of the Exclusive Brethren.

However Erin Bay claims the Open Brethren also operate a system based on power and financial control.

"There's a saying that for the Brethren, God comes first, until it comes to money," he said.

"And then God comes second."