A court in Malta has rejected a request that would have prevented FBI agents from testifying in pre-trial proceedings in the murder case of a prominent investigative journalist.

Judge Lorraine Schembri Orland dismissed on Monday an attempt by Alfred Degiorgio – who, along with two others, is accused of killing Daphne Caruana Galizia – to stop the FBI from giving evidence in the case.

Caruana Galizia was killed on October 16 after a bomb exploded in her car as she drove away from her home in Mosta, a small town outside the capital, Valletta. She was 53.

American FBI agents along with Dutch forensic experts have been helping Maltese authorities to solve the case.

Degiorgio’s lawyer argued that his client’s rights would be prejudiced if foreign experts were allowed to testify because they had worked with Martin Bajada, a court-appointed information-technology expert who was convicted of theft and fraud in the 1990s.

“Dr Bajada should never have been appointed in the first place and should never have been allowed to work alongside the FBI experts,” Degiorgio’s lawyer said.

In her ruling on Monday, Judge Schembri Orland said: “Apart from the fact that the public nature of the judicial process is in itself a guarantee of a fair hearing, this complaint has nothing to do with the context of this case and is therefore simply frivolous and vexatious.

“There is nothing in the request that induces this court to conclude that there is an imminent risk that the investigators are not going to testify on the data they gathered and give their conclusions and evaluations.”

Caruana Galizia’s death sent shockwaves throughout the small island country and prompted international condemnation.

She was well-known for her popular blog, Running Commentary, where she highlighted alleged high-level corruption by politicians across party lines.

Caruana Galizia also covered criminal gangs and drug trafficking and was responsible for exposing Malta’s links with the so-called Panama Papers document leak.

The FBI is due to give evidence in the case on Tuesday.