The customers had signed up to the mennica24.pl website, which offered gold coins and bullion bars for sale, deliverable within 60 days of purchase.

According to aggrieved clients, though, these were not received.

The Prosecutors Office in Kraków, which is supervising the police investigation, told TVP World: “At the moment 14 people have filed reports of suspected crimes, paying a total of 449,297.83 złotys (€105,000) for gold bullion coins and gold bars.”

It added that the company behind mennice24.pl, Kraków-based Grupa Mennice Polskie Sp. zo.o., is accused by the customers of “misleading” them “about the intention and possibility of fulfilling the contract for the sale of goods in the form of gold bullion coins and gold bars purchased through the online store.”

Grupa Mennice Polskie Sp. z o.o, meanwhile, has denied all wrongdoing.

In an email sent to TVP World, it said: “There’s no such situation. We have delays in carrying orders out, but we are fulfilling orders.”

The allegations came to light when gold coin trader Jacek Jakubiuk interviewed two investors for his YouTube channel Finansowy Preppers, which covers investment topics, after seeing their complaints on an online investors group called Fundacja Trading Jam Session.

Jakubiuk told TVP World: “Since I spoke to those first investors, I have spoken to five other people in the same situation.

“The first signs that people were not getting coins delivered from mennica.pl was in October.

“By now, if they were making 5-10 million złotys per month (€1.2-2.5 million), and they could have been at the below-market prices they were offering, the amount scammed could be over 100 million złotys (€25 million).”

He added that, in normal circumstances, around “90% of gold coin trades are transacted over the counter, like buying a pack of cigarettes, with gold handed over directly.

“Courier delivery times rarely exceed four days.”

Grupa Mennice Polskie Sp. zo.o. said: “Every year we have several thousand orders, we have been on the market for 15 years, one of the first such firms in Poland.

“The majority of the information in the articles is written without any verification or contact with us.

“We will be preparing a lawsuit for defamation and damages to our company.”

Kraków prosecutors have since confirmed that during the investigation, which is looking at cases starting in October 2023, “two of the injured parties had provided information that they had received purchased products worth a total of 32,191.35 złotys (€7,500)."