One of the men who carried out the deadly attacks in Brussels on March 22 had worked as a cleaner in the European Parliament six years earlier.
In a statement on April 6, the EU Parliament said the individual had month-long summer jobs there in 2009 and 2010.
Although the EU Parliament did not reveal his name, sources identified him as Najim Laachraoui, a 25-year-old Belgian who prosecutors said blew himself up in the airport attack and is also suspected of making suicide vests for last November's Paris attacks in which 130 people died.
The Belgian prime minister defended his country's approach to fighting terror threats, insisting Belgium is not a "failed state."
Charles Michel said authorities had to take a share of the blame for failings before and after March 22, when attacks claimed by the Islamic State militant group killed 32 people.