A man with a rare form of blood cancer has travelled 10,000 miles to meet the stranger who saved his life.

Luke Melling, 31, from Melbourne, Australia, says he was “staring death in the face” before receiving a stem-cell transplant from Alastair Hawken, of Grantham, Lincolnshire.

The match between the pair was so perfect that the men now believe they could be distantly related, as both their families hail from Preston, Lancashire – the town they chose for their emotional first meeting.

They are sharing their story to encourage more people to join the NHS Stem Cell Donor Registry.

Three years ago, Luke, who was then 28, was desperately ill in hospital with Hodgkin lymphoma.

He had been living with the condition since he was 16 and, despite being in remission four times, the cancer kept coming back.

After exhausting all other treatments, he was told he needed a transplant of stem cells – which can be found in the bone marrow and produce essential blood cells – to survive.

But no-one in his family, and no-one in Australia, was a match, so doctors started searching global stem-cell registries for a donor.

“It was pretty much like, ‘This is it – this is the only option you have. It’s either this or you’re going to die’,” Luke says.

“Finding out that my sister wasn’t a match was terrifying – we just didn’t know if there would be anybody registered who would be a suitable match for me.”

But then, after a six-month wait, Luke was told there was hope. The register had discovered a potential donor on the other side of the world.

“When we found out we had the perfect match, that was an emotional moment,” Luke recalls. “I remember mum – she was in hysterics, crying.”

For Alastair, then 48, the phone call came out of the blue. A regular blood donor, he had signed up to the NHS registry in 2008.

When he was asked if he was still willing to donate, the father-of-three did not hesitate.

“It was no problem at all,” he says. “What can I do, where can I be? It was nice to be wanted, or to feel that I could be of use to someone.”

Before the donation, Alastair was injected with a high-strength cell-generating drug. After a couple of days he could barely move, but he was told that showed the process was working and the body was “over-generating stem cells”.

He then went to a hospital for the stem cells to be “harvested” in a process similar to blood donation, while he was fed snacks and watched television.

“There’s no discomfort,” he says. “The stem cells are taken out and packaged up, and then they’re counted in the laboratory – 85 million is what we needed for Luke, and that’s what was taken.

“I felt amazing – my body was made up of fresh stem cells – and then my [harvested] stem cells went on their journey.”

The cells were cryogenically frozen within hours to be sent to Australia, where Luke was waiting.

Luke had his transplant a month later, but all he knew about the donor was that he was a 48-year-old man from the UK.

He was not allowed to contact Alastair until two years had passed and the treatment was considered successful.

At that point, Alastair did not know whether Luke had survived.

“I just hoped. I hoped and prayed that he had,” he says.

And then an email dropped into his inbox via the stem cell registry.

“It was like all my Christmases had come at once,” Alastair recalls. “It was a really beautiful moment.”

The men were put in contact with each other and finally met in Preston on Friday.

Luke told Alastair: “To have someone like you, who is so beautiful, lovely and kind, having done all this, I’m glad it’s your cells. I just can’t thank you enough.”

For his part, Alastair, who runs a gingerbread business, describes the donation as his “legacy”.

He told Luke: “If I achieve nothing more than just seeing that smile on your face, then I’ve achieved everything I need to achieve.”

Preston was a fitting place to meet as Alastair’s grandparents lived in the town and Luke’s family also have roots there.

Luke, who is now 31 and back to full health, feels he can put the last 15 years behind him. He has even run a marathon.

“Meeting Alastair in person is a dream come true,” he says. “What do you say to the person who has given you your life back by literally giving a part of themselves?

“Me being able to get on that plane and fly across the world is possible only because of him.

“The moment I got to give him that huge hug and thank him in person is a moment I’ll never forget.”

Alastair, now 51, hopes their story will encourage others to sign up to the stem cell registry.

“Meeting Luke today really brings home just what a difference that simple act can make,” he says.

“I just wish more people would put themselves forward to be on the register to donate, whether it’s platelets or organs or blood or stem cells – that is just the gift of life.

“There’s nothing that makes you feel more complete as a human being – and when it’s a success story, like it clearly has been in our case, it makes everything all worthwhile.”

Additional reporting by Paul Johnson

The NHS is encouraging more people aged 17-40, from all ethnic backgrounds, to join the NHS Stem Cell Donor Registry, to give more patients a better chance of finding the life-saving matches they need.