Ingvar Kamprad, the founder of the global furniture retailer Ikea, is known for buying his clothes at flea markets, driving an old Volvo and flying only economy class. Although he is a billionaire many times over, he revels in his reputation for saving money.

Now, European regulators are accusing Mr. Kamprad’s company of pushing the concept of thriftiness beyond the limits of the law by maneuvering to reduce its tax bill in the countries where it operates.

The European Commission, the European Union’s executive arm, said on Monday that it had opened an investigation into Inter Ikea, one of the retail giant’s two main divisions, amid concerns it may have been given unfair tax advantages by the Netherlands, where Inter Ikea is based. The inquiry is part of an intensifying campaign by European regulators to crack down on what they view as sweetheart deals between multinational companies and tax-friendly countries that have sought to draw their business.

The announcement adds Ikea to a list of firms targeted by European officials for using sophisticated strategies in Ireland, the Netherlands and other European Union countries to pay few or no taxes on billions of dollars of profits. Other companies facing similar scrutiny include Starbucks and Apple