Telegram is a encrypted messaging telephone application that claims to have 100 million monthly active users.
Law makers fear that dangerous jihadists are using it to hide what they want to say and plot sinister attacks in Europe and beyond.
The 19-year-old man who attacked a Catholic church in France last month allegedly used Telegram.
For this reason, Germany and France are calling on the European Commission to draft Europe wide rules legislating these kind of encrypted telecommunications networks.
Speaking at a joint press conference in Paris, French and German interior ministers Bernard Cazaneuve and Thomas de Maziere called for new measures that would limit the use of encrypted communications across the EU.
They want these measures to be discussed at an EU summit in Bratislava on 16 September. The ministers also want a data registrar set up for all visitors to the EU free-travel Schengen zone and more shared intelligence among European police forces.