The latest sitting in the Daphne Caruana Galizia murder case has been postponed after suspect Yorgen Fenech was too unwell to attend court.

Fenech, who is accused of conspiring to kill the journalist, is sick with an undisclosed illness, the court heard.

Prison officer Elenio Galea presented a doctor's certificate to the court when it resumed on Monday morning to hear the compilation of evidence against the businessman.

Self-confessed murder middleman Melvin Theuma was due to complete his testimony against Fenech.

Galea said Fenech, who is being held on remand at Corradino Correctional Facility, woke up on Monday morning, complaining that he was unwell. A doctor conducted a check-up and confirmed he was sick.

His lawyers told the court they wished his privacy to be respected and the cause of the illness was not disclosed in court.

Lawyers for the Attorney General and lead prosecutor, Superintendent Keith Arnaud, asked the court to go ahead with Theuma's testimony, saying it was "perfectly legal to do so."

Jason Azzopardi, lawyer for the Caruana Galizia family, also called for the sitting to continue, claiming there would be a greater prejudice to the case if Theuma's evidence was not concluded. This is the gathering of evidence stage or proceedings, so the defence would suffer no prejudice should it continue, he argued.

However, defence lawyer Charles Mercieca said their client should be present while the testimony is revealed so that they could consult with him in real time.

"It's not capricious that he is not here today," he said. 

Magistrate Rachel Montebello agreed with the defence, deeming the request justified. 

Theuma has been testifying about secret recordings he made of conversations with a series of people linked to the case, including Fenech and his business associate Johann Cremona.

The final recording to be presented to the court is 45 minutes long, the court heard.

Court will resume on Thursday, June 3.