Leiden steps up summer inspections amid rise in illegal sex work in student housing

The municipality of Leiden is intensifying summer inspections after reporting a seasonal rise in illegal sex work. The student housing is identified as a particularly vulnerable setting alongside hotels and vacation apartments, the municipality reports. The enforcement will be raised in cooperation with the Haags Economisch Interventie Team (HEIT), landlords, housing corporations, and the hotel sector. The city is also urging residents, students, and hospitality workers to report suspicious activity.

Officials say warning signs can include frequent short visits by mostly men, people photographing buildings or house numbers, men being picked up at entrances by women, and behavior suggesting residents or guests are deliberately avoiding attention.

Officials say student housing is especially exposed during summer months because many students temporarily leave the city to stay with family or travel abroad, while international students often return to their home countries. This leaves many units empty and reduces oversight, making it difficult to determine who is actually residing in the housing. Authorities say this combination increases the risk of illegal prostitution going undetected.

The municipality stressed that the cases do not involve students performing sex work from their own dorms, but rather external individuals temporarily using the units.

Data from the HEIT shows illegal sex work in The Hague's student housing across municipalities has been identified 16 times in 2026 so far. The figure was 10 in 2025, 16 in 2024, 5 in 2023, and 1 in both 2022 and 2021. In Leiden specifically, HEIT recorded 2 cases so far in 2026, compared with 3 in 2025 and 5 in 2024. Officials say earlier years did not indicate a clear structural issue in the city, though they caution the real number is likely higher based on online monitoring of sex advertisements.

Authorities say student housing cases in Leiden typically involve self-contained studio units in larger student complexes, often occupied by international students, rather than shared student houses. They say these environments have limited day-to-day social control due to short stays, high turnover, and reduced contact between neighbors.

Hotels and vacation apartments are also identified as risk locations, particularly where online check-in systems allow guests to access rooms without interacting with staff or a reception desk.

Officials say the issue is linked to a broader shift since the COVID-19 pandemic, when online sex advertising increased and activity moved away from licensed venues toward private residences and temporary accommodation.

While sex work is legal in the Netherlands, it is subject to conditions designed to prevent exploitation. Authorities warn that illegal sex work can conceal sexual exploitation and human trafficking.

Leiden Mayor Peter Heijkoop said, "Illegal sex work often takes place behind closed doors. That is why reports from landlords, hotel staff, students, and neighbors are of great value. By staying alert together, we can identify abuses earlier and intervene when necessary.”