The family of Daphne Caruana Galizia expressed hope the guilty plea by Vince Muscat on Tuesday afternoon will serve as a step towards full justice for the murdered journalist.

In their first reaction to one of the three alleged hitmen admitting his role in the October 2017 car bomb, the family said he had robbed her "of her right to live, to cherish her family and her grandchildren who were born after she was killed."

Shortly after Muscat entered his plea, it was revealed that three more people have been arrested in connection with the murder. Police seized brothers Robert and Adrian Agius and their associate Jamie Vella on suspicion of supplying the car bomb. 

Parte civile lawyer Jason Azzopardi read out a statement in court on behalf of the family, shortly after Muscat's lawyer said his client would be admitting all charges.

"The macabre murder of Daphne Caruana Galizia was intentional and could have been avoided. The victim paid with her life and her family are paying for the loss of their loved one," Azzopardi said.

"I said all this today because if Daphne's family had to respond to the plea bargain based on their emotions, their response would be obvious," Azzopardi said. 

The statement ended with the family expressing hope the development would "lead to full justice for Daphne Caruana Galizia". 

In the past weeks, Muscat had been working with the authorities to reach a plea deal with prosecutors. He will likely serve a reduced sentence in exchange for a confession and testimony about other co-conspirators.