It may be some hours before police will know if there is any evidence at an Adelaide factory, as part of a renewed search for the missing Beaumont children.
Police addressed the media at the North Plymton site at around 12.30 local time, revealing there was nothing of significance to report.
"We have our fingers crossed, we hope for the best but we do want to temper expectations," he said.
"Clearly we have an anomaly which we need to investigate."
That anomaly was uncovered recently through scientific testing on the site by Flinders University. Two brothers also told police they had been asked to dig a large hole on the site at the time the Beaumonts went missing.
Police say they are still around 80cm from the anomaly, after digging through close to two metres of soil.
The children never returned after leaving their parents' Glenelg home for an afternoon at the beach on Australia Day, 1966.
This is the second time police have excavated the site, with an initial dig proving fruitless.