What happened to the Beaumonts? One last search for Arnna, Jane and Grant at Castalloy factory site in Adelaide

A site that many suspect holds the answer to our greatest unsolved crime will be dug up one last time before it goes into the hands of developers.

• Beaumont family breaks silence

Ground will be excavated at the former Castalloy factory site in Adelaide for the third and final time to look for the missing Beaumont children before the land is developed.

The private dig at North Plympton, organised by independent state MP Frank Pangallo, will take place later this month and reinvestigate two sites along with a third which has never been searched before.

While past digs in 2013 and 2018 were unsuccessful, Mr Pangallo said it would “eliminate this theory once and for all”.

“We can’t be sure but evidence did emerge that perhaps the children were buried here at Castolloy,” he said.

“The disappearance of the Beaumonts is easily Australia’s greatest unsolved crime.

“In short, we do not want to go on wondering whether or not their remains are here.”

It will be the third dig to take place at the site following unsuccessful attempts in both 2013 and 2018.

Independent MLC Frank Pangallo. Picture: Naomi Jellicoe

Arnna, Grant and Jane Beaumont disappeared from Glenelg on January 26, 1966.

The first dig was prompted after two brothers told police that they had dug a grave-like hole at the site at the request of owner Harry Phipps two days after the children vanished.

Phipps, who died in 2004, had been a long-time person of interest in the case with his son accusing him of sexual abuse and playing a part in the Beaumont’s disappearance.

Former major crime detective Bill Hayes has spent decades following the case and said he was optimistic the dig would bring Australia a step closer to finding the truth.

“Justice for us has always been finding the children and finding out what happened to them and returning them to the family for a decent burial,” he said.

“We don’t know what the hole was dug for but was it pure coincidence?”

The dig will start on February 22 with the state government allowing the site to be searched for seven days.

In the event remains are found, the dig will cease immediately and SAPOL will be contacted, Mr Pangallo said.

Detective Superintendent Des Bray inspects the dig site during the last investigation in North Plympton in 2018. Picture: Roy Vandervegt

SA Police officers examine material in the pit in 2018. Picture: Greg Higgs

SA Police investigation at the Castalloy factory in North Plympton in 2018. Picture Greg Higg

Independent MLC Frank Pangallo (centre) pictured with former investigator Bill Hayes and Flavio Anfiteatro from Flavio and Sons Civil. Picture: Naomi Jellicoe

Flavio and Sons Civil have donated their services for the search with owner Flavio Anfiteatro more than happy to help.

“It’s gonna be a huge dig,” he said.

“We’ve purchased some earth moving equipment that’s quite large to accommodate the dig and my sons are quite happy to put this new electronic system to use.”

He said that the coordinates that they’ve been given which have been previously searched hadn’t dug deep enough.

“We now want to go twice as deep than they did last time just to make sure so hopefully if there’s anything there, we’ll find it,” he said.

The Beaumonts have been missing since January 26, 1966 after failing to return home from Glenelg beach that afternoon.

Despite widespread search operations, Jane, 9, Arnna, 7, and Grant, 4, were never found.

Almost 60 years since they vanished without a trace, their family has broken years of silence to call for a coronial inquiry into their disappearance.

While there’s no telling what will be found, hopes are high that the site may hold the key to solving the decades-long mystery.

Originally published as What happened to the Beaumonts? One last search for Arnna, Jane and Grant at Castalloy factory site in Adelaide