Key Points:

The extraordinary story of two babies switched at birth in a Dunedin hospital on Christmas Eve 1946 is about to be revealed in a new book.

A lively, dark-skinned boy who should have been raised a Lebanese Catholic instead grew up in a middle-class Presbyterian home, and a reserved fair-haired Anglo-Saxon lad took his place.

It was almost 60 years before Jim Churchman and Fred George discovered the truth through DNA tests.

How the hospital mix-up occurred has not been established.

Only one of the four parents, Helen Churchman, is still alive.

She is my aunt, and she has taken the discovery of a new son with courage, dignity and great happiness.

Helen, 86, remembers Jim being given to her in hospital on that day in 1946 and wondering why he seemed much darker than his older brother and father.

But Helen's mother had a darkish complexion, as did some of the cousins. It was also thought that Jim's looks could come from Welsh ancestors.

Fred stood out even more, although his mother, Ngaire, came from Caucasian stock and married into the Lebanese community.

Perhaps Fred's looks came from a Scandinavian ancestor, it was suggested.

"I used to have these peculiar feelings of being in another world, or in someone else's identity," Fred recalls.

"But I have been brought up in the middle of the Georges. You can't tear that away.

"I love my family [the Georges], and one of the things I realise is that I love them whether I'm a George or a Churchman."

The truth might never have emerged but for a schoolyard friendship that began in Timaru in about 1961.

Helen's husband, Gordon, was teaching there and Jim was sent to Timaru Technical College.

Fred's brother Michael, who was a year older, was sent from Dunedin to board in Timaru.

At school Jim Churchman and Michael George met and became close friends.

When the Churchmans returned to Dunedin, Jim resumed the friendship and would often visit and have meals with the Georges - and the woman who was, as it turned out, his natural mother.

The Churchman family had early suspicions that everything didn't seem quite right. Gordon had asked hospital authorities to confirm Jim was their birth baby when Jim was a teenager.

He was told there was no mistake, and he told the family that was to be the end of the speculation.

"I think in a way he was protecting me," Helen said of her husband yesterday.

Jim trained in engineering, working as a marine engineer and in meat processing plants, before setting up in business in Hamilton, selling and installing spa pools.

Fred left school at 16 and worked in all sorts of jobs around Dunedin before touring the world with a social rugby team in his mid-20s.

He met an Italian American and settled in Massachusetts, working primarily as a baker.

Fred has just completed and published a book on his life called Switched At Birth: My Life in Someone Else's World.

In it, he describes 2002 as a watershed year. In the years before, two brothers and his father died of heart attacks.

Two other brothers had heart operations and Jim also had serious cholesterol problems.

Jim started thinking more about his genes and family susceptibility to medical problems.

He had often remarked on how Fred was so like his brother Owen. With that in mind, Jim and Fred had DNA tests, which confirmed the switch.

Despite the previous questions, the results "took my breath away", Fred says.

Fred's daughter Jessica was visiting New Zealand at the time and Jim, concerned about the shock of the news to Helen, decided to take Jessie along to soften the blow.

So Fred's daughter met his mother before he did.

"Once we had concrete, undeniable proof that a terrible mistake had been made 57 years before, other things started to come together," Fred said.

"Jim really had the George temperament. Temperamentally, I've always been more conservative, more like a Churchman, even before that was a consideration.

"No matter who brings us up, our genes will follow us until we die."

All the families' photos now made sense - Fred so like the fair Churchmans, including a hint of ginger, and Jim dark like the Georges, with Ngaire's rosy cheeks.

When I came to meet Fred, I was struck, like everyone else, how like birth brother Owen he is in looks, speech and mannerisms. They even put a finger up to their face in the same way when they talk.

Fred told me that when he was about 18, he was in the Burnside meat works cafeteria when a man came up to him and said, "You must be Owen Churchman's brother".

Fred said he did not know Owen Churchman, but one of his brothers was a friend of Jim Churchman.

When Fred came to New Zealand in 2004, the Georges and the Churchmans got together in Dunedin to mark their new links.

Despite their different backgrounds, the families gelled and it was a happy occasion.

"I don't expect to displace Jim. I know there is room enough in her [Helen's] heart for both of us," Fred says of his relationship with his birth mother.

For those of us in the wider family, the news three years ago that Jim was born a George, and Fred a Churchman, was astonishing.

Yet, somehow, the surprise was tempered because we all knew Jim was different. He is the cheeky live-wire, popular among us cousins, smart and practical.

Life growing up was not always easy for either boy.

Both stood out from their brothers and sisters in looks and personality. Neither felt he fitted in.

Ngaire George suffered, at times, from the suspicion that Fred might have been the result of an affair.

Helen Churchman has some regrets about what might have been, but she still treasures her Jim.

"Jim is as good to me as any son could ever be," Helen said yesterday.

"I'll always be his mum.

"But I also would have loved to blow Fred's nose and pull up his socks when he was a wee boy."

But she bears no grudge about the mix-up.

"I don't feel bad about what has happened to Fred. He is in a good place and has a nice wife and family.

"It makes me feel good that he had a loving and lovely mother [Ngaire George]," Helen said.

We in the wider family have been astounded at the force of genetic heritage - not just in appearance but also personality and manner.

We've been so pleased that both Jim and Fred were able, through remarkable happenstance, to know their birth mothers, and we've marvelled at the strength of the bonds between Jim and Fred and their other mothers.

Fred's son Adam has since been to New Zealand, doing his best to make contact with lots of Georges and Churchmans. And Jessica, when she visited, found she shared a strong interest in naturopathy with her birth aunt Jane.