Public claims by Alfred and George Degiorgio implicating “prominent people in politics” in Daphne Caruana Galizia's assassination are an attempt to derail pending murder proceedings, the slain journalist's sister warned on Saturday.

Corinne Vella warned that the hitmen's claims, made in a statement in which they argued they were being victimised by hidden hands wielding great power, had to be seen in the context of their convictions. 

George Degiorgio, she noted, had told a Reuters journalist that murdering Caruana Galizia was "business as usual" for him. 

"He was willing to blow up Daphne’s car when other members of Daphne’s family were travelling with her, to collect payment for killing Daphne herself," she said.

"Rather than face a jury trial and lifetime imprisonment, George and Alfred Degiorgio admitted to killing Daphne and have been sentenced to 40 years in prison.

"The Degiorgios’ and another murderer’s convictions for Daphne’s contract killing are thanks to a small group of people working - at great risk to themselves - to bring all of Daphne’s murderers to justice.

"The attempt by two of Daphne’s murderers to derail pending murder proceedings should be seen from this perspective," she added. 

The Degiorgio brothers are serving a 40-year jail term after pleading guilty to their role as hitmen in the 2017 car bomb that killed Caruana Galizia. 

Fellow hitman Vincent Muscat, il-Koħħu, has also admitted to planting the bomb along with the brothers. 

Others allegedly involved in the murder remain on trial: Yorgen Fenech is alleged to have paid the hitmen to kill the journalist, using taxi driver Melvin Theuma as a middleman; Maksar brothers Robert and Adrian Agius and their associate Jamie Vella are alleged to have supplied the bomb that the hitmen used.

Corinne Vella, one of Caruana Galizia's sisters, was unimpressed by claims made by the Degiorgio brothers. Photo: Jonathan Borg

In their statement on Saturday, the Degiorgio brothers made a number of serious but unsubstantiated claims. 

Caruana Galizia, they claimed, was being monitored by the secret services in the days before her 2017 murder.

They said they could provide evidence of a number of other crimes and alleged that the police had failed to act on information they provided them.  

They also cited various people, including former ministers Carmelo Abela and Chris Cardona, former OPM chief of staff Keith Schembri, lawyer David Gatt and former police commissioner Lawrence Cutajar as having an interest in burying "the truth".