Nearly 52 years ago, the Beaumont children vanished. Now investigators have a new lead.

Almost 52 years ago, three children went missing from an Adelaide beach, and so opened investigation that would become one of Australia’s most infamous cold cases.

Now, an investigation by an Australian news team may just lead to the case finally being solved.

On Australia Day in 1966, the Beaumont children – Jane, nine, Arnna, seven, and four-year-old Grant – left their parent’s nearby home to take the short bus ride to Glenelg Beach.

As unusual as that might sound now, it was normal for the time, and the kids had a successful trip to the beach the day before.

This time though, they never returned home.

It's thought that the children were kidnapped at some point during their outing, perhaps even on their way home. However, despite leads and witness claims of seeing the children playing with a "blond man", police have never been able to track down the Beaumont's abductor.

This recent break in the case came via Seven News, who during a year-long investigation into the disappearance found that a possible, previously searched, gravesite was probably searched in the wrong spot.

This month, researchers using new technology found that an area of the Castalloy factory in Plympton, near Glenelg, had been disturbed. The disturbed land measured one metre wide, two metres long and two metres deep - perfect for a gravesite.

What's more, if this site is found to be where the children's remains lie, it will strongly suggest the identity of the killer, Seven News reports.

An Adelaide businessman, Harry Phipps, who owned the factory and died in 2004, was indirectly fingered as the killer in a 2013 book written about the case, The Satin Man. In it, though he is not named Phipps' son, Haydn said on the day the Beaumont children went missing he saw them in the backyard of his father's home, a short distance from the beach where the children were playing. Phipp's was later named as the man, prompting to two men to come forward saying he asked them to dig a trench on his property around that time.

"He was a paedophile, he was a predatorial [sic] paedophile and he was a dangerous man, we know that," former SA police detective Bill Hayes told Seven News.

South Australia Police told the Daily Mail this new information about earth disturbances has led them to reexamine the site and they are planning an excavation in the coming weeks.