Faqir Malyar, a carpet trader from the western German city of Gelsenkirchen, was on his way to visit one of his customers during the Christmas holidays when he heard news on the radio of an astonishing bank heist. Thieves had drilled a hole in the wall of the vault of a local Sparkasse – savings bank – and made off with the contents of almost 3,250 deposit boxes.

The robbery, likened by a police spokesperson to the Hollywood film Ocean’s Eleven, made international headlines: it is estimated that the thieves’ haul could have been worth as much as €300m (£260m), a sum that would make it the one of the biggest bank heists in a country wearily familiar with them.

Calling it an “unprecedented crime”, the chief investigator, André Dobersch, criticised attempts on social media to make light of the case. “We’re not talking about safe-crackers in a comic,” he said, “but about criminals who’ve caused sleepless nights … and destroyed livelihoods.”

Police believe that a 300kg drill was used to bore a hole in the vault wall. Photograph: Gelsenkirchen Police Handout/EPA

For Malyar, the news was deeply alarming. The Gelsenkirchen Sparkasse was where he kept his savings as well as family heirloom jewellery. He fears his dreams of retiring soon with his wife have now gone up in smoke.

“I hoped against hope that my deposit box wasn’t one of those that had been plundered,” the 67-year-old said. But after spending 45 minutes waiting in a queue for his call to a bank hotline to be answered, he was told his box, number 1,413, was among more than 3,000 to have been emptied. “I felt as numb as if I’d had an injection,” he said.

Police believe the thieves carried out the theft over a four-hour period on 27 December. Having gained access to the bank from an adjoining car park through a manipulated emergency exit, they then set about boring a hole with a 300kg drill into the vault’s wall.

Police were only alerted 48 hours later after a fire alarm was activated and they arrived to find the break-in. CCTV footage shows the masked suspects – believed to be between five to seven men – leaving the car park in a black Audi and a white Mercedes van, both bearing stolen number plates. Three weeks after the heist, the suspects are still at large.

In the days after the heist, customers gathered outside the bank in angry and emotional scenes, chanting “let us in” and demanding information. Malyar and the thousands of others whose money and valuables have gone want answers from the Sparkasse: what level of security did it have? Were its surveillance systems fit for purpose?

Police officers outside the branch of the Sparkasse. Photograph: Christoph Reichwein/AP

Jürgen Hennemann, an insurance lawyer who since 2012 has represented the victims of more than two dozen bank robbery cases in Germany, most of them involving the savings banks, said criminals were becoming increasingly brazen as banks failed to address security shortfalls.

“The banks have been constantly warned over 13, 14 years that they are in the crosshairs of organised crime,” he said, adding that despite this many had failed to act. The result: “The attacks are getting more and more intense; the robberies are happening ever closer together.”

Hennemann is representing a number of customers of the Sparkasse in Norderstedt near Hamburg, which in one of the more spectacular heists of recent years was broken into in 2021 by criminals who rented the apartment above and drilled through the concrete ceiling to gain access to 650 safety deposit boxes. Losses there are estimated to have been between €11m (according to the bank) and €40m (according to the lawyers representing the customers).

A white Mercedes van with fake number plates was one of two vehicles used by the thieves. Photograph: Police Gelsenkirchen/AFP/Getty Images

Klaus Nachtigall, the former head of Berlin’s criminal police office, now a security consultant, said he was not surprised by the theft in Gelsenkirchen: “There are now so many such cases, but the financial institutions don’t seem to want to learn from them.”

“It’s upsetting to know that these acts are preventable. If security systems are working, the alarm should sound at the first sign of a piece of debris falling out of the wall,” he told local media.

So far the Sparkasse network, which consists of about 342 lenders serving about 50 million customers, has said it can give little information while the police investigation is continuing. About** **230 officers have been assigned to “Operation Drill”.

But, in a statement, Sparkasse Gelsenkirchen defended its security measures. “We can only say that our security technology meets recognised state-of-the-art standards. We ensure this through our collaboration with specialist companies. Within the last two years, the burglar and fire alarm systems in our buildings have been inspected and upgraded,” it said.

Michael Klotz, the head of the Gelsenkirchen branch, said both the bank and its customers had been “victims of a burglary carried out with highly criminal energy and using complex technology”, telling the local newspaper WAZ that they were in a “constant race between security technology and criminals”.

For those who have lost their savings that is unlikely to bring much solace. Many people have said their Sparkasse boxes contained items with a value of €40,000 or more. A lot have been shocked to learn that the basic insurance policy will cover only up to €10,300 a box.

One of the suspects. Photograph: Police Gelsenkirchen/AFP/Getty Images

Hans Reinhardt, a lawyer who is preparing to represent many of the Gelsenkirchen victims in the event of legal action, said his clients, including a man who had been planning to fund his retirement via gold bars worth €600,000 he had stored in the vault, had seen the items as protection against catastrophe.

“Many people told me that out of fear of war and inflation they had moved away from stocks and bank accounts, investing in gold instead. Some said they kept larger sums of cash on hand so they could access it quickly if needed,” he said.

Malyar, meanwhile, said his carpet shop, around the corner from the bank, had become a meeting point for victims. “I dish out tea,” he said. “I have become something of a counsellor to those in a similar position who come by to share their woes with me.”