Convicted drug baron Mario Camilleri, nicknamed l-Imnieħru, died of a heart attack caused by a blood clot – not from gunshot wounds, a court heard yesterday.

Two court experts told Magistrate Antonio Micallef Trigona two holes found in Mr Camilleri’s skull were not recent wounds because scar tissue had already grown on them. No bullets were found, nor was there any evidence of gunshots to the head, they said.

Neurosurgeon Antoine Zrinzo and forensic expert Mario Scerri were testifying in the compilation of evidence against two men charged with killing Mr Camilleri, 51, and his 21-year-old son, Mario.

Jason Galea, 40, of Birżebbuġa and George Galea, 42, of St Julian’s are denying murdering the Camilleris, whose bodies were found partly buried in a shallow grave in a field in Qajjenza, Birżebbuġa, in July 2013.

The body of Mr Camilleri Sr was exhumed soon after burial to settle a conflict between investigators and medical examiners on the cause of death.

The police have independent declarations indicating that Mr Camilleri died after he was shot but medical examiners insist he succumbed to a heart attack.

Mr Zrinzo was appointed by the court to examine two holes found in the skull during the second autopsy. Dr Scerri was asked to report on the outcome of the second autopsy and on the deceased’s medical history.

Mr Zrinzo testified that the holes found in the skull were possibly “burr holes”, which had been made a long time before death, so much so that they had begun to heal. Moreover, no entry wounds were found in the skin, with the holes covered by “mature scar tissue”.

He noted that the holes could have been the result of a medical procedure to test intra-cranial pressure, although they were not in the place usually associated with this kind of procedure.

Dr Scerri said the second autopsy confirmed the conclusions of the first one: Mr Camilleri Sr had died of a heart attack caused by a blood clot in his coronary artery.

The second autopsy was carried out by Bridgette Ellul, who is yet to testify on her findings.

Dr Scerri said that the medical file he had examined showed that Mr Camilleri Sr had a history of chest pain and high blood pressure, and had visited the hospital on numerous occasions to be tested and treated for these ailments.

He said the cause of death of Mr Camilleri Jr was blood loss due to multiple wounds.

The case continues. Lawyer Giannella de Marco is appearing for George Galea. Lawyer Joe Giglio is representing Jason Galea.