Window prostitution brothels in the Netherlands are disappearing, and there are now just around 1,000 red light work spaces in Dutch towns and cities, compared with 1,500 some 15 years ago.

Rooms with a red-lit window now feature in fewer than 10 cities, Trouw said on Wednesday, based on local authority figures. The forced closure of sex workers’ premises because of nuisance and criminality is the main reason for the decline, the paper said.

Utrecht banned window prostitution completely in 2013 because of human trafficking concerns.

The notorious red light district in Amsterdam has also been reduced in size. Over the years, some 150 windows have been shut because of official council policy, and The Hague now has more windows than Amsterdam.

Other cities, such as Groningen, Leeuwarden and Alkmaar have also drastically reduced the number of windows. Alkmaar closed 140 windows because the premises had been bought using ransom money from the kidnapping of beer magnate Freddy Heineken in 1983.

Brothels were legalised in 2000 and local authorities had hoped to be able to facilitate and regulate prostitution, said Yannick Bleeker of research bureau Regioplan. “But in practice this boiled down to repression,” he said.

Another reason is the sex industry shift to the internet. Window prostitution is increasingly seen as old fashioned, he told the paper.

Officials expect window prostitution to continue to decline, the paper said, with Groningen and Deventer planning to transform their red light properties into homes and shops.

Amsterdam is planning to move a further 100 window prostitution rooms to an erotic centre near the RAI conference centre to relieve pressure on the city centre, although that is still at the planning stage.

Other legal prostitution venues, such as clubs, are also becoming less popular, said André van Dorst of sex club owners’ organisation Vereniging Exploitanten Relaxbedrijven.

“Demand is growing, but the number of safe workplaces is falling,” he said. That could lead to an increase in illegal and unregulated prostitution, he said, making window prostitution even more unappealing. “Old window owners can’t sell their business for love nor money,” he said.