The way Apple tells customers about product warranties is being scrutinised across Europe.
The European Commission has asked members to find out if Apple is letting customers know about their right to a minimum two-year warranty.
Consumer groups in 11 nations have complained that Apple has emphasised its own after-care service over statutory protections.
Apple said its service gave different protections to customers.
Bloomberg reported that Europe's Justice Commissioner Viviane Reding has written to member states to check if Apple's advertising mentioned the two-year minimum warranty.
Ms Reding said in many cases Apple was only mentioning the one-year warranty it offered rather than the statutory protection. "These are unacceptable marketing practices," wrote Ms Reding.
An Apple spokesman declined to comment but referred Bloomberg to information about statutory protections on its website.
In late 2011, Apple was fined £750,000 (900,000 euros; $1.21m) by Italian competition authorities who argued in court that it had not done enough to let people know about their rights under EU consumer laws.
Those laws say firms must replace a product if it does not work when it is first taken out of its box and switched on. By contrast, Apple's paid-for service contract provides for a replacement if the gadget breaks once it starts to be used.