Amsterdam brothel keepers must keep to the stricter rules the city imposed on them in 2013, the Council of State has ruled.

The city’s more stringent policy is aimed at protecting prostitutes who rent space in the city’s window-based brothels. They include a minimum age for prostitutes of 21 and an obligation on brothel keepers to interview prostitutes in order to spot signs of human trafficking.

Earlier appeals to change the rules ,which brothel owners said were impractical, had been successful but mayor Eberhard van der Laan lodged an appeal with the Council of State shortly before he died. The country’s highest administrative court has now upheld almost all of the rules he introduced.

The council did agree that a rule requiring brothel keepers to be at the premises within 12 minutes in order to talk to council inspectors was too strict, as was the responsibility for the cleanliness of the rooms and sex toys.

The council also ruled that sensitive information from the interviews between brothel keepers and prostitutes does not have to be shared with the local authorities.

The decision by the Council of State is irrevocable and leaves no room for another appeal, the Parool reported.