Excavation of an Adelaide industrial site, which could be the resting place of the Beaumont children, will be carried out on Friday, police have confirmed.
A range of experts will be involved in the work at the New Castalloy site at North Plympton, with digging to begin about 8am.
The New Castalloy site was formerly owned by Adelaide businessman Harry Phipps, who died in 2004 but is still considered a person of interest in the case.
Police said a forward command post will be established on the property, with digging to occur at the site of an anomaly identified by experts.
An anthropologist from SA Forensic Services will be on site, along with police from Major Crime and Forensic Response, a member of the SES and an expert from Flinders University.
The Beaumont children – Jane, 9, Arnna, 7, and Grant, 4 – disappeared from Glenelg Beach on January 26, 1966.
The North Plympton site has been investigated before, but became a renewed focus of police efforts in recent months.
Recent geophysical testing uncovered a small anomaly at the spot where two brothers said they dug a hole for Mr Phipps the same year that the Beaumonts disappeared.