Greek Prime Minister Kyriakos Mitsotakis has ordered a speedy investigation after a veteran crime journalist was shot dead on Friday.
Giorgos Karaivaz was shot at least six times with a silenced weapon by two men on a moped outside his home in Athens.
His death “shocked us all,” said a government spokeswoman.
Media freedom organisations said it must be established whether Karaivaz was killed for his work, which covered organised crime and corruption.
European Commission President Ursula von der Leyen urged justice for the “despicable, cowardly” murder.
European Parliament speaker David Sassoli tweeted that he was “devastated” by the news.
The last killing of a journalist in the EU to have caused such outrage was that of Jan Kuciak in Slovakia three years ago.