ROME (Reuters) -Italy’s antitrust regulator said on Tuesday it opened an inquiry into possible price-fixing for flights in and out of Sicily by airlines including Ryanair, Wizz Air and easyJet.

The probe follows a complaint by consumer group Codacons, which alleged “a specific collusive will” of airlines to raise prices for domestic flights to and from Sicily during the Christmas holidays, the regulator said in its weekly bulletin.

The complaint also targeted state-owned ITA Airways, the successor of former flagship carrier Alitalia, it added.

In a statement to Reuters, easyJet denied any wrongdoing.

“easyJet strongly refutes these claims, adheres to relevant laws and regulations and will fully cooperate with the authorities to demonstrate it has always acted lawfully and competitively in the best interests of consumers,” it said.

The other involved airlines did not respond to requests for comment.

The cost of flights is particularly sensitive in Sicily, whose many natives who live and work in northern or central Italy typically wish to travel back to the island to spend Christmas with family and friends.

The antitrust authority said its inquiry would come to an end by Dec. 31, 2023.

(Reporting by Angelo Amante in Rome;Editing by Alvise Armellini, Matthew Lewis and Emelia Sithole-Matarise)