Laws kicked in last year making it illegal for landlords to rent out apartments to short-term visitors, with a penalty of up to €100,000 (S$158,400).
Renting out rooms is allowed provided they do not cover more than 50 per cent of the entire floor space. Owners of second homes took the authorities to court and won, allowing them to rent out whole apartments.
Last week, the city authorities made a fresh set of proposals that would force homesharers to register. They would be allowed to let out their properties for only 60 days in a year.
In 2014, Airbnb was fined €30,000 by Catalonia's government for breaching laws stating that properties targeting tourists must be registered with the authorities. In 2015, the company was fined US$65,000 (S$87,000) for breaking the same law. Barcelona has doubled its illegal rentals squad, and will have more than 100 by next year.
In July, Airbnb finally agreed to take down adverts for apartments that are not on an official register.
One of Airbnb's most popular cities with nearly 90,000 listings, the authorities have a similar squad that conduct raids on homeowners who flout regulations, such as renting out their flats for more than 120 days a year.
The authorities have also demanded that the site remove offers that do not have a registration number, a requirement that entered in force on Dec 1.
The authorities have clamped down on illegal homesharing such as when homeowners bust the limit of 60 days a year, and more than four people at a time.
This year, it imposed a record €297,000 fine on an Airbnb landlord and agency. The Labour Party, which is in opposition in the Dutch city, wants to ban homesharing sites like Airbnb ahead of next year's local elections.