People queue outside an Apple store in Paris on November 18, 2019 | Stephane Sakutin/AFP via Getty Images French set to slap antitrust fine against Apple from Monday

France's Autorité de la Concurrence is set to fine U.S. tech phone maker Apple as soon as Monday for including illegal restrictions in its contracts with wholesalers, according to two sources with knowledge of the case. A third person confirmed the decision was "imminent."

The French antitrust watchdog investigated Apple and three of its wholesalers Tech Data, Ingram Micro and Virgin Mobile for entering into illegal agreements at the expense of Apple's premium resellers, such as eBizcuss.com, court documents show.

The probe started after eBizcuss.com lodged a complaint with the Autorité in April 2012, two months before the company was wound up. In parallel, eBizcuss.com claimed damages before a French court.

The antitrust agency's investigation was slowed down by Apple contesting the legality of the watchdog's dawn raids in 2013. French courts concluded the searches were legal in 2018.

The fine the authority will give Apple is expected to be among the biggest individual fines — if not the biggest — the watchdog has ever set, according to one source.

Other record fines the authority slapped to individual companies include €350 million on telecoms operator Orange, €196 million on transport company Géodis in 2014, and €189 million to cosmetics maker L'Oréal in 2014.

The Autorité de la Concurrence and Apple declined to comment.