The failure of Maltese authorities to identify the masterminds behind the murder of investigative journalist Daphne Caruana Galizia raises questions about the rule of law in Malta, according to Europe's chief human rights watchdog.

Caruana Galizia, whose reporting uncovered widespread corruption, was killed by a car bomb in October 2017. Her murder exposed the dark side of the Mediterranean island that is both a member of the EU and a haven for online gambling, offshore finance and cryptocurrencies.

In the draft of a report seen by Reuters and due to be released on Wednesday, the Council of Europe concludes Malta's rule of law is undermined by weak checks and balances on power and says more must be done to strengthen judicial independence and bolster law enforcement.