The family of a toddler who disappeared from an Australian beach more than 50 years ago have criticised police for not formally interviewing potential eyewitnesses during a review of the case.

Officers suspect three-year-old Cheryl Grimmer was abducted from Fairy Meadow beach, which is about 50 miles (80km) south of Sydney in New South Wales (NSW), when she went missing on 12 January 1970. The Grimmer family had only just emigrated from the UK.

They have now been told the review, which took four years to complete, has not brought up any new evidence that could lead to a conviction.

They are angry that three potential eyewitnesses who spoke to the BBC were not formally interviewed by officers, despite their contact details being passed to police.

Ricki Nash, Cheryl's brother, said he felt total frustration about the way the review had been handled, which he understood was meant to be a detailed, full review of the case.

There are no words, just nothing, he said of the decision not to formally interview the potential eyewitnesses. Our family can't move forward without the help of the police.

The three potential eyewitnesses came forward after the BBC aired the Fairy Meadow true crime podcast in 2022, which has since been downloaded five million times.

One man, who asked to keep his identity private, said he had seen a teenage boy carrying away a small child from changing rooms beside the beach on the day Cheryl disappeared.

The man said he had a brief chat over the phone with NSW Police after telling the BBC about what he saw, but did not hear from the force again.

Damian Loone, a retired detective who worked on Cheryl's case, said he believed the man's testimony was very credible.

In 2017, a man in his 60s was charged with Cheryl's abduction and murder after officers discovered a confession made to police by a teenage boy in 1971. A judge later ruled the confession could not be presented as trial evidence.

The defendant - known only by his police codename Mercury because he was a minor at the time of the alleged offences - was freed in 2019 and all charges, which he denied, were dropped.

In a new episode of the Fairy Meadow podcast, former Det Sgt Loone said he just can't fathom why the police did not formally interview the man who spoke to the BBC, something he would have done if he was still in charge of the investigation into Cheryl's disappearance.

I think that's sloppy police work, he added. That's what they should have done and I can't believe that it hasn't happened.

Cheryl's brother Ricki, now 62, was seven years old when she disappeared. The pair had been together in changing rooms beside Fairy Meadow beach but after he turned away for a few seconds, she was gone.

Cheryl's family continues to seek justice and clarity regarding the circumstances surrounding her disappearance, urging the NSW Police to revisit their methods in cold cases like theirs.