"It's been practically impossible to get an apartment unless you've paid for this service and that's not OK," property company Gavlegårdarna spokesman Johan Stark told Sveriges Radio (SR).
When the company recently listed several apartments in eastern Sweden for rent online, the flats disappeared off the list within minutes. Suspecting foul play, Gavlegårdarna looked into the matter, only to find that another computer had been set up to monitor the listings site and nab flats as soon as they appeared online.
The company said that it suspected one person was behind the software, collecting a fee of up toward 3,000 kronor ($460) to get apartments for clients.
Gavlegårdarna has now improved its website security.