A volunteer team using cadaver detection dogs to search for the body of a British child who disappeared in Australia more than 50 years ago has found an “area of interest”.

The group hopes their finding is a breakthrough into Cheryl Grimmer’s case and have reported the location to New South Wales Police, who are now on the scene.

Authorities suspect the three-year-old, who’d emigrated from Bristol with her family, was abducted from Fairy Meadow beach in Wollongong in January 1970.

“A search will be conducted tomorrow with the assistance of specialist officers as part of ongoing inquiries,” police told the BBC in an emailed statement.

Today, bathed in the sun, the beach looks as idyllic as it must have been all those years ago. From the sand dunes, looking inland, the terrain gradually climbs into dense bushland.

A short drive up into the hills, there’s a small pocket of woodland on the edge of an upmarket suburb that could reveal a terrible secret.

Balgownie was the location mentioned in a confession made by a teenage boy – also from England – a year after the toddler vanished. Decades later, a judge disallowed that admission.

In 2019, a trial of the suspect, known only by a codename, Mercury, who’d been charged with Cheryl Grimmer’s abduction and murder, collapsed. The man, in his 60s, had denied any wrongdoing.

Cheryl’s brother Ricki Nash was seven when his little sister vanished. He last saw her in the changing rooms at Fairy Meadow.

“This should have been done 55 years ago,” he said as the specialist team with dogs trained to detect human remains began its work. “My question is, why wasn’t it?

“Yes it’s extraordinary. The police have never canvassed this area in detail even though they had a confession. Not just a confession, a very detailed one.”

He has spent a lifetime craving answers, but doesn’t want to find them here among the tall trees, creek and bushes.

“We always live with the hope that someone took her that couldn’t have a child, raised her well. One day she’d grow up, find out she didn’t belong to that family. We’ve had people over the years do that to me and to our family: knock on the door and say that they are Cheryl and your heart rate goes at a million-to-one.

“We were hoping for it to be Cheryl one day. So, to be here looking for a body or part thereof, I mean, it’s not a good thing,” Mr Nash told the BBC.

Nine-year-old Rufus is the principal search dog. His handler is Chris D’Arcy, the president of Search Dogs Sydney, a charity, who’d offered to help the Grimmer family after attending a missing persons seminar in Wollongong. He’d also heard the BBC’s Fairy Meadow podcast, presented by Jon Kay, which has been downloaded five million times.

The canine team has had success in previous cold cases dating back more than half a century. Last year, they found human remains in a lake in northern New South Wales.

Now, Mr D’Arcy’s team believes it has made a potential breakthrough in the Grimmer case.

“What we believe we have located is an area of interest and will pass the information on to the authorities,” he said. “The dog showed a distinct change in behaviour.”

Ricki Nash said the news made him “tremble”.

“If it is Cheryl out there – she has been there for 55 years now – she shouldn’t have been,” he said.

Balgownie was mostly farmland in 1970. Frank Sanvitale, a former detective who worked on the Grimmer case, has come to support members of Cheryl’s family. They have become close and share deep frustrations about the broader police investigation over the decades.

“To find something after 55 years, I’m hoping we do, but the chances are one in a million,” he explained. “It would be like winning four lotteries in a row. You’ve got to use a bit of common sense and be sensible and logical about it.”

The retired investigator has challenged the individual or group responsible for the toddler’s disappearance to come forward.

“What about doing something for Cheryl, that little girl you took away and owning up to what you did and [giving] families here in Australia and in England… some peace,” he said.

Tragedy sends ripples of grief through families. Ricki Nash’s daughter, Melanie Grimmer, has four children. She is also anxiously waiting for news of the search at a command post on the side of the road.

“I know my dad hopes that nothing is found. I hope she’s found, I hope the baby girl comes home. My family has been through so much and it is a continuous fight,” she told the BBC. “I feel sick in my stomach being here.”

Much has changed since 1970. But one thing remains steadfast – the determination of a grieving family to uncover the truth.