The last time they were together was 51 years ago in England, when she was just nine-months-old, and Ms Bergin has been doggedly searching for him since.

“My mother was independent, six years older than dad, and decided to do things for herself,” she said.

“All she told me about my dad was that his name was Anthony Brown and he was originally from Wales.”

The prevalence of his name hindered Ms Bergin’s search – she had nearly given up, until six weeks ago.

“In England, we have a BBC program called Heir Hunters, and the the owner saw my plea and decided to see if he could help,” she said.

“It took him about five hours to get back to me, and he said, ‘This gentleman is not in the UK’, and I went, ‘Just my bloody luck’.”

Through tracking down the wife of Mr Brown’s brother, Ms Bergin suddenly had an Australian phone number.

“When I called it was a flood of tears – we both couldn’t speak,” she said.

“Within a month, I flew out and arrived here on May 2.”

It turned out, Mr Brown had done his own searching.

“I was running a pub in a place in Westminster – most of my customers were government officials, and I got to know a barrister,” he said.

“I was feeling a bit down one day and he said ‘What’s the problem?’.

“I said, ‘I had an affair with a very good friend and she’s had a little girl, and they’ve just disappeared’.”

The barrister traced Mr Brown’s former lover, Anne, to the Channel Islands but there were no more leads.

“I said, ‘I’ve got to get myself a life’, and came to Australia in 1975,” he said.

“I had a heart attack in 2006 and the doctor said, ‘We nearly lost you’.

“There’s someone watching over me and Katie and they’ve brought us together, I’m certain of it.”

Ms Bergin had one more surprise for Mr Brown, 77, and his wife, Marge – that he has a granddaughter – and Grace, 21, would visit soon.

But for now, father and daughter have plenty more cups of tea to talk over.

“We’ll start chatting at 7am, and next thing I know it’s 9.30am –  we’re two peas in a pod,” Ms Bergin said.

“He said to me, ‘It’s like the moon and the stars have finally arrived back on Earth’, and that’s what it’s like.”