Watch: Kiwi siblings living an hour apart meet for first time in their 50s

If it hadn't been for a DNA test kit, Susan and Terry could have gone all their lives not knowing they had a sibling.

Instead, the two New Zealanders in their early 50s have recently found out they are related, and have a whole other extended family they never knew existed.

Susan Butler, 52, and Terry Smith, 51, met recently after a lifetime of not even knowing the other existed, despite living a mere hour or so away from each other (Susan lives in Te Puke and Terry in Whakatane).

Terry's mother never told his father she was pregnant with Terry and she never told Terry who the father was.

Suddenly Terry was finding out about his father and siblings he never knew he had, thanks to a free DNA kit he used to find out more about his family history.

"It was awesome, especially for my father," Susan told the Herald. "I thought I knew all the siblings I was ever going to know."

"I got the test results on 19 July and messaged all these Terry Smiths."

It didn't take her long to find the right Terry Smith. The first phone conversation was emotional for both and they agreed to meet as soon as possible.

Susan and Terry met for the first time after a DNA test kit told them they were related. Photo / Supplied

"It was quite weird too because five days before finding this out, we went out to dinner for my father's birthday, in Whakatane, so we were right there, so close," she recalls.

Susan and Terry wasted no time. They knew enough time had been wasted. There was only one night between finding out the test results and actually meeting face-to-face.

Susan and Terry's father never knew Terry existed so and is delighted to have found out about his son.

"For me to have found our sister and my father, it's a lot," Terry said the day they met. "Fifty-one years without a father and all of a sudden I have all this other side of the family. It's just changed my life."

It all started when Susan Butler, 52, received a kit from MyHeritage due to the DNA Quest initiative.

The global initiative gifts free DNA test kits to people who have been adopted, in the hopes of helping them finding their biological family.

Butler, from Te Puke, always knew she was adopted but thought she knew all her family anyway.

Still, like 160 other Kiwis, she applied for the "DNA Quest" programme and received her free kit.

She was going to gift her free test to someone else but decided to start filling out the form to figure out how easy it was. Then curiosity got the better of her.

She was fairly convinced there was no one else for her to meet but, still, something told her it was possible she was wrong.

"I think I have siblings, my birth mother died in 2003. My birth father may also have other children. I would be interested to find out," she wrote in her application.

Her shock quickly turned to joy when she received the results.

"I highly recommend the test but be careful it might reveal some skeletons as well," she said.

For people to match on the DNA Quest initiative, they both have to had taken the test, which is why the tests are so important.