The regions of Alpes-Maritimes, Var, Bouches-du-Rhône, Ardèche, Rhône, Haute-Savoie, Vendée, Maine-et-Loire and Morbihan were part of the trial - but tax officials say it may now be rolled out nationwide.

The discovery of thousands of undeclared private swimming pools in France has provided an unexpected windfall for French tax authorities. Following an experiment using artificial intelligence (AI), more than 20,000 hidden pools were discovered. They have amassed some €10m ($9.9; £8.5m) in revenue, French media is reporting. Pools can lead to higher property taxes because they boost property value, and must be declared under French law. The software, developed by Google and French consulting firm Capgemini, spotted the pools on aerial images of nine French regions during a trial in October 2021.

France experienced its worst drought on record last month, and officials have since been cracking down on conserving water. Now a new artificial intelligence (AI) technology could be added to their arsenal, after it successfully uncovered 20,356 illegally-built private swimming pools. The country's tax authority announced yesterday that the system allowed it to collect about €10 million (£8.5 million) from homeowners who failed to report the facilities. Developed by Google and Capgemini, the AI software was trained to spot pools in aerial images of nine French departments. The results of a trial run last October were then cross-checked with land registry databases, before Direction generale des Finances Publiques (DGFiP) took action.

The regions of Alpes-Maritimes, Var, Bouches-du-Rhône, Ardèche, Rhône, Haute -Savoie, Vendée, Maine-et-Loire and Morbihan were part of the trial - but tax officials say it may now be rolled out nationwide.