Workers installing sewage pipes in Sint-Gillis-Dendermonde, East Flanders, discovered 49 gold bars and thousands of coins hidden in a sealed cellar wall. The estimated value of the find is around €EUR9 million ($AUD14.6 million).
One worker on the project spoke to the media and said the discovery initially caused disbelief and amazement.
"At first I thought they were €EUR1 coins. But then we also saw a gold nugget lying there,” he said.
“That's when we realised it was something bigger."
The workers reported the discovery to the police, who secured the gold and transferred it to a government facility. Authorities are investigating whether the hoard is connected to criminal activity.
The property, known as Brouwershuis, was built for brewery owner Theophilus Van Assche in the 19th century. CAW Oost-Vlaanderen, a social welfare organisation that provides welfare support in Dendermonde, a Flemish community of around 47,000 people, currently owns the property.
Its director hopes any share of the treasure will support its work. Belgian law allows the rightful owner five years to claim the hoard. If unclaimed and cleared of criminal links, the gold could be split between the finders and the property owner.
More reading
Who We Were & What We Wore
Rare collection of gold jewellery and burial objects found in Egypt
3,500-year-old gold jewellery unearthed in Greece
Tudor Heart: British Museum launches appeal for golden pendant
Treasure hunters strike deep-sea gold and silver