Spanish property rental portal Idealista has already taken down the amusing ad for a street bench in Madrid's upmarket Salamanca neighbourhood.

The "advertisers" managed to bypass the site’s quality control tests and uploaded a picture of a Spanish "banco" (which is the same as the Spanish word for a bank) with the following description: "Classic structure, wooden and metal finish, a housing style that’s proving to be a hit in Greece, Portugal and Italy".

Although the ad may have come across as a simple prank to most readers, the perpetrators were looking to denounce Madrid’s strict new bylaws, one of which makes beggars pay €750 ($1,000) fines if they're caught asking for money.

"It’s disgraceful that people sleeping rough are being fined," prankster Íñigo Andiarena told the Spanish edition of The Huffington Post.

"If you get a €750 fine for begging, sleeping rough on the street bench is just as expensive as a luxury flat in the city.

"We’ll carry on posting the ad on different rental sites to show that right now the highest rental costs in Madrid are for people sleeping on street benches: €750 for two square metres."