The European Commission has initiated what could be the start of an anti-trust probe against the so-called “E5” group of major European operators, reports the Financial Times.

Competition officials in Brussels have reportedly requested information about meetings that have taken place since 2010 between Deutsche Telekom, France Telecom, Telecom Italia, Telefónica, and Vodafone.

According to the report, it is unclear whether the Commission is targeting a specific issue emerging from the meetings. However, it notes that the decision to demand information usually reflects specific concerns in the Commission and is the first step in collecting evidence to justify more serious action – though sources say a formal investigation has yet to be launched.

Industry body the GSMA confirmed it has “recently received correspondence from [Directorate General for] Competition which we will respond to in due course.”

One person close to the situation contacted by the Financial Times expressed surprise at the inquiry given the presence of a lawyer at each meeting, and notes sent to the European authorities about the content of the discussions.