Updated November 19, 8am

Malta’s top criminal investigators say they have identified a group of “more than two” Maltese nationals who they believe masterminded the killing of journalist Daphne Caruana Galizia.

The family say they have not been 'formally' informed.

High ranking officers who are leading the murder probe told The Sunday Times of Malta that the investigation into who commissioned the car bomb was at a “very advanced stage”, with the main suspects now having been identified. However, there was no indication of how much longer the investigation could take.

The investigators believe these people had different motives for carrying out the assassination but came together to contract the three men accused of having planted and triggered the bomb.

Contacted on Sunday, Ms Caruana Galizia's sister Corinne Vella said the family was not formally informed by the police that the suspected masterminds had been identified.

The sources would not give any indication of who these suspects were or whether they came from the criminal, business or political world.

The question: How has Daphne's murder changed Malta?

Home Affairs Minister Michael Farrugia appeared to confirm that suspects had been identified on Sunday evening.

Speaking to Italian TV channel Rai 3, Dr Farrugia said that investigators had "concrete" evidence linking the suspects to the crime. He declined to provide any further details.

The investigators say they are in constant contact with Europol – the EU’s law enforcement agency – over the case, but in recent weeks this contact has intensified significantly as police get closer to cracking the case. “We have a large amount of data that requires analysing and partners like Europol have the necessary experience and expertise to help facilitate this process,” a source said.

Other Maltese officials involved in analysing financial transactions said a paper trail of evidence was being established, however this was not yet “concrete”.

Partners like Europol have the necessary experience and expertise to help facilitate this process

Investigators say that they have more evidence in hand but did not divulge any further details.

Ms Caruana Galizia was assassinated by a car bomb explosion in October 2017 just a few metres from her Bidnija home.

The murder sent shockwaves through the local and international community who have united in a call for justice and an end to impunity for the killing.

According to a newly released report, Police Commissioner Lawrence Cutajar has told MEPs looking into the state of rule of law on the island that the murder probe “has reached a delicate stage”.

Meanwhile, brothers Alfred and George Degiorgio and Vincent Muscat have been in custody for 11 months, since their arrest on December 4 in the former potato shed-turned criminal headquarters in Marsa.

A few days later they were accused of carrying out the car bomb murder and pleaded not guilty.

The court proceedings against the three has so far detailed how the police, working with agents from the US Federal Bureau of Investigation, used cell phone and telecommunications tower data to discover how the bomb had been detonated and by whom.

It has also heard how the three men enjoyed lavish lifestyles despite being unemployed, owning luxury cars, sending their children to private schools and gambling large sums of money at Malta’s casinos.

Sources said there was a time when they had hoped one of the three men would cooperate with investigators in a bid to find the mastermind. However, all three men remained tight lipped under interrogation.