Last year the unit received 15,554 notifications of suspect transactions from the various institutions that report financial data. These were principally the banks, bureaux de change and customs authorities. Like those establishments, notaries and estate agents are obliged by law to report any financial transaction they think might be a sign of money laundering.

The number of notifications was 27% higher than in 2007, when it was also up by about a quarter on the previous year. But the large rise in notifications did not lead to an increase in the number of charges brought, Delepière said. “In many cases, there are several notifications relating to the same case.”

In addition, many transactions that are reported turn out to be legal. Customs authorities must, according to a law of 2007, conduct an inquiry into any cross-border movement of more than €10,000 – but those are not necessarily criminal. The €10,000 limit also applies to bank accounts and currency-change transactions, where there is no cross-border requirement.