BRUSSELS (Reuters) - Increased European scrutiny of a police investigation into the killing of a journalist in Malta reveals the degree of international concern about the rule of law on the Mediterranean island, one of the journalist’s sons said on Tuesday.

Anti-corruption blogger Daphne Caruana Galizia was killed by a car bomb in October near her house. Maltese authorities have charged three men with carrying out the murder but have not identified those who ordered it.

The Parliamentary Assembly of the Council of Europe (PACE), a pan-European body with 47 member states, appointed on Monday Dutch parliamentarian Pieter Omtzigt to monitor and report on the Maltese police investigation.

The Council of Europe, a rights watchdog, is distinct from the 28-nation European Union. Malta is a member of both.

“This monitoring is unprecedented for an EU member state. It shows the extent of the worry in Europe about the situation in Malta,” said Andrew Caruana Galizia, the journalist’s son.

The EU’s justice commissioner said on Monday she would visit Malta soon to see how the investigation is progressing and to look at its anti-money laundering moves.

Omtzigt has a mandate to ensure that the murder is “thoroughly and impartially investigated... without political interference,” according to a PACE motion presented earlier this year that paved the way for his appointment.

A press officer for the Council of Europe said it would be “the first time that the Assembly has prepared a report on the issue of an individual murder in an EU member state”.

The body has so far monitored murder investigations in only two cases, both in Russia, which is not in the European Union though it is a member of the Council of Europe.

The move came as a group of local and international media groups, including Reuters, began following up stories covered by Caruana Galizia, in an initiative called the Daphne Project.

Maltese authorities say they do not know the motive for the crime. A one million euro reward offered by the government for information remains unclaimed.