Owen Bonnici was arriving at a meeting with a European Union delegation and Prime Minister Joseph Muscat to discuss the 2017 car bomb killing, when he was confronted by the protesters shouting "shame on you".
Muscat was also heckled as he arrived at the meeting. He has defended his government's handling of the murder investigation and called for national unity after days of protests. On Sunday (December 1) he said he would step down next month.
Police have charged one of Malta's wealthiest businessmen with complicity in the killing. He has denied accusations and pointed the finger at members of Muscat's inner circle.