Police have uncovered a criminal network which used falsified mortgage papers in a large-scale scheme to buy up hundreds of houses in the Amsterdam region between 2018 and 2023.

The scam came to light during an investigation into people specialising in creating hidden spaces in cars and buildings to store drugs, the Financieele Dagblad reported.

The main suspect in the case is a drugs criminal turned real estate agent who bought dozens of houses using fake documents in 2023 alone, police found. The houses were used to store drugs and money and house mostly Bulgarian labour migrants.

The network headed by the man consisted of six mortgage advisory firms, financial services companies and other real estate agents, the paper said.

The mortgage advisors would file bogus mortgage requests with banks based on fake credentials, such as payslips and annual accounts at least twice a month. In total, police estimate 800 houses were bought this way since 2018.

“This is also impacting on normal law-abiding citizens who have been done out of a house,” Amsterdam public prosecutor Ursula Weitzel told the Financieele Dagblad.

It is likely the same scam is being perpetrated in other cities. “It is almost impossible to tackle,” she said.

In May police arrested 10 people linked to the scam. Since then 12 others have been held on suspicion of fraud, money laundering, and forgery. Police seized the contents of seven safes, cash, watches and jewellery during searches of the suspects’ homes.

Banks are not able to distinguish the bogus paperwork from the real thing, and should be given more information by the tax office, police said. They also recommend police and the justice department should provide information about people who request a mortgage on a structural basis.

Under the current law, that is only possible in rare cases and under strict conditions.