Builders renovating a house in Belgium have discovered a stash of gold reportedly worth €9 million (£7.6 million) sealed inside the walls of a cellar. The find has sparked questions over who may ultimately be entitled to keep it.

Construction workers stumbled across the hidden trove of gold bars and coins while drilling to lay new sewage pipes at a property in East Flanders earlier this week, according to local media reports.

Among those who made the discovery was an 18-year-old working a summer job, identified as Kobe.

"Our first reaction was actually disbelief, amazement," he told Belgian public broadcaster VRT. "At first I thought they were €1 coins. But then we also saw a gold nugget lying there. That's when we realised it was something bigger."

The workers promptly alerted police and made clear they had no intention of keeping the find. Site manager Mario explained why holding onto it was never a realistic option.

"There are so many coins and bars - it would be almost impossible," he told VRT. "Besides, that would be theft."

Kobe agreed: "€9m – you simply can't keep that hidden."

Police launched an investigation and warned the public against visiting the site in search of further treasure, stating that the house had been "turned upside down" and that all the gold had been moved to a secure location.

In an unusual move, the local police force updated its Facebook profile picture to an image of a gold coin. Officers said they hoped the discovery would end up in "the right place" and change people's lives.

The property belongs to CAW Oost-Vlaanderen, a welfare organisation serving Dendermonde, a Flemish community of around 47,000 people.

Its director, Geert Hillaert, said his initial reaction was one of "surprise and amazement." He expressed hope that the treasure might eventually be used to support the charity's work and address the "enormous need we experience daily."

Under Belgian law, the rightful owner has five years to come forward and claim the hoard. The local prosecutor, who has opened an investigation, said it was not yet known who that might be.

If no owner successfully claims the gold, civil law provides that hidden treasure found on another person's property be divided between the finder and the property owner. That provision applies only if the hoard is not found to be connected to criminal activity.

Both the builders and the charity now face a wait of up to 1,823 days to learn whether anyone will step forward.