Google’s Paris offices have been raided by hundreds of French investigators—the search giant is suspected of avoiding tax in the country to the tune of €1.6 billion (~$1.78 billion, £1.22 billion).

The French financial prosecutor’s office (Le parquet national financier, PNF) which carried out the raid in the early hours of Tuesday morning, confirmed that the searches were the result of a preliminary investigation opened in June last year into possible “aggravated tax fraud and organised money laundering.”

Google’s European headquarters are based in Ireland, which boasts a tiny 12.5 percent corporation tax—the lowest in the European Union.

French authorities are probing if “Google Ireland Ltd is permanently established in France and if, by not declaring some of its activity on French soil, it has failed to meet its fiscal obligations.”

Google said: “We comply with the tax law in France, as in every other country in which we operate. We are cooperating fully with the authorities in Paris to answer their questions, as always.”

The raid on Google's French headquarters included 25 IT experts.

In January, Google reached an agreement with the UK’s tax authorities to pay £130 million in back taxes. But HMRC was criticised for accepting such a small settlement.