French authorities are investigating Apple’s contracts with the country’s mobile operators, according to the Wall Street Journal.

An administrative body under the French finance ministry is looking into the contracts between mobile phone suppliers and operators for device sales, including the iPhone, according to a person familiar with the matter.

The inquiry is part of a wider investigation that is looking into the relationship between handset vendors and leading operators. According to one source: “For operators, handsets have become one of the big expenses. There is a balance of power that is shifting.”

No one from Apple or the finance ministry’s antifraud and antitrust units were available to comment.

The Apple enquiry was first reported by French TV channel BFM TV.

This is not the first enquiry by authorities in Europe into the US company. Earlier this year, the European Commission is thought to have sent out a questionnaire to operators about Apple’s distribution deals with the aim of establishing whether they are designed to close out rival smartphone vendors.