According to information provided to The Washington Post, Foreign Minister Péter Szijjártó has frequently contacted his Russian colleague Sergei Lavrov to report on what has been discussed at various EU meetings.
The European Commission now expects an explanation from the Hungarian side.
The data... is seriously worrying. A relationship based on trust between the member states and the EU institutions is fundamental to the work of the EU, says spokesperson Anitta Hipper at a press briefing in Brussels.
Szijjártó has called the information "fake news", while Hungarian Prime Minister Viktor Orbán has ordered an investigation into possible wiretapping.
