Shortly after Greek singer Giorgos Mazonakis, 54, collapsed during a plasma exchange treatment at an Athens clinic and was taken away by ambulance with no detectable heartbeat, the doctor treating him deleted all calls and messages she had exchanged with him before the incident. The singer was pronounced dead later that day. Dr. Ioanna Gaka also deleted all her correspondence with Mazonakis' hypnotherapist, according to findings by Greek police investigators submitted to an investigating magistrate and revealed by the newspaper Proto Thema.
Investigators also discovered searches on Gaka's phone that have raised serious questions. Earlier reports revealed that doctors at the clinic had searched ChatGPT for resuscitation instructions. Now, investigators have uncovered further searches by Gaka, including questions to artificial intelligence tools about how to bring someone out of sedation.
She also searched for the side effects of propofol, a powerful intravenous anesthetic, what happens when it is combined with midazolam, another sedative sold under the brand name Dormicum, and whether a drop in blood pressure could be a side effect of the two drugs. She even searched whether propofol was available in pill form.
Those searches have taken on new significance following a report by Greek television channel MEGA that preliminary toxicology tests detected propofol in Mazonakis' body. Gaka has maintained from the outset that she did not administer sedatives to the singer. The tests are being conducted at the University of Thessaloniki's toxicology laboratory, which has requested another sample to determine the concentrations of the substances detected. Final results are expected by the end of the week.
Messages exchanged by clinic employees suggest they, too, knew what had happened. According to the investigative findings, staff members wrote in a group chat that the singer had been given a sedative that caused his blood pressure to fall sharply, prompting them to call an ambulance.
The clinic's 28-year-old secretary testified that after emergency services were contacted, she messaged her partner saying Mazonakis had apparently suffered cardiac arrest because of a reaction to the sedative. Police are now trying to establish how the substances reached the clinic, since facilities of this type are not permitted to possess them.
'He told me he had no money, but I went ahead'
Mazonakis, one of Greece's most beloved singers for the past three decades, arrived on September 9 at the clinic run by Gaka and her husband in Athens' upscale Kolonaki neighborhood for plasmapheresis, a procedure involving the removal and processing or replacement of blood plasma. Both doctors have since been detained on suspicion of homicide.
In testimony to the investigating magistrate, excerpts of which were published last week, Gaka denied the allegations against her and insisted that the treatment was entirely safe.
She said the singer had initially hesitated because of the high cost. "He told me he didn't have the money for the treatment, but I went ahead because it was Mazonakis. I was doing him a favor," she testified.
Mazonakis' hypnotherapist also testified that the singer had reservations about undergoing the procedure.
In the same testimony, Gaka admitted that she had not reviewed the singer's medical history before connecting him to the machine. "I didn't take a medical history, but I saw all the measurements we performed. I didn't ask him to bring recent medical test results," she said.
According to Gaka, Mazonakis told her he had not slept and wanted to sleep during the treatment. She also claimed that she had not performed plasma exchange at all, but rather a procedure involving "double filtration of the plasma."
In her account, the treatment was repeatedly interrupted because of damaged veins. During one break, the singer went to the bathroom and returned in good condition. About half an hour later, while Gaka was attempting to locate another vein, his condition suddenly deteriorated.
"Suddenly, while I was watching the monitor, I saw his heart rate slowing and his oxygen level dropping from 98 to 89," she testified. She said his blood pressure also fell to 100/60, from an earlier reading of 140/90.
Gaka described placing an oxygen mask on the singer, calling her husband, instructing a nurse to prepare adrenaline and beginning cardiopulmonary resuscitation. According to her account, emergency services were called approximately five minutes later.
One nurse said after the incident that the clinic's defibrillator had not been working because it had not been charged. Gaka argued that the device had not been needed because the monitor showed asystole, a cardiac arrest rhythm characterized by the absence of detectable electrical activity in the heart.
The paramedic who arrived at the clinic testified that Mazonakis already had no pulse and that his pupils were dilated.
Gaka also denied ordering the treatment room to be cleaned after the incident. "I wasn't the one who asked for the place to be cleaned. I wasn't in any condition to ask for anything. I was in complete shock. The nurses did it on their own initiative," she said.
Husband distances himself from his wife
Gaka's husband, Dr. Ilias Theodoropoulos, is no longer presenting a united defense with her. He has adopted a separate legal strategy, claiming that he did not even know Mazonakis had scheduled an appointment with his wife at their shared clinic. He also maintains that he had never been in contact with the singer or examined him.
However, according to one nurse's testimony, Theodoropoulos told staff on the day of the incident that Mazonakis had died and added that "we all share responsibility."
Gaka's legal team has also undergone a series of changes. The lawyers who initially represented both doctors withdrew from her defense because of the couple's conflicting accounts and continued representing her husband.
Their replacement, Nikos Alexandris, resigned after two days. Attorney Petros Pantazis subsequently took over her defense, and his office quickly clarified that Gaka had never authorized her previous lawyer's public statements.
(Photo: Instagram)
An autopsy found no evidence that Mazonakis had suffered a heart attack, and the pathologist described his heart as completely healthy.
However, according to MEGA's website, a finding has now been identified in tissue samples taken from the singer's heart. Investigators are trying to determine when the abnormality developed and whether it could be connected to treatments he underwent before his death, including procedures at the same clinic, one of them just a day before he died.
Mazonakis' personal physician, who was also a close friend, said the singer had undergone extensive medical examinations several months before his death.
"Giorgos underwent laparoscopic surgery to remove his gallbladder in February, here at Metropolitan Hospital in Faliro. He underwent thorough examinations from head to toe: CT scans, MRI scans, complete blood tests and cardiac examinations," the physician said.
Asked what the tests had shown, he replied: "He was perfectly healthy. There was absolutely no reason for Giorgos to leave us."
Forensic medicine expert Dr. Dimitris Galenteris cautioned against drawing definitive conclusions from those earlier examinations. "Changes can occur within a short period. That is why we always conduct tests before every procedure. Tests from three or four months earlier are not sufficient to proceed with a new operation or any other medical intervention," he explained.
What the examinations did establish, he said, was that the singer had no chronic illnesses that threatened his life. The Athens Medical Association, which has already joined the criminal proceedings alongside the prosecution, has also requested a separate investigation into the couple over alleged false declarations.
According to the association, the doctors submitted two documents in 2025 and 2026 describing their plasma exchange machines as components of a device used for ozone therapy. The association's president, Giorgos Patoulis, said at the beginning of the case that plasma exchange procedures are legally performed in the Athens area at only three public hospitals.
In her testimony, Gaka insisted that the association had been fully aware of her equipment. "I didn't hide the machine. I declared the machines to the association. The first one, which was purchased in 2023, I declared in 2025," she said.
Eurovision winner joins tribute to Mazonakis
As the investigation continues, Greece is still mourning the singer. The new season of the Greek edition of The Voice, on which Mazonakis served as a judge, premiered over the weekend with an episode dedicated to his memory.
The episode opened with a joint musical tribute by the show's coaches, including Helena Paparizou, winner of the 2005 Eurovision Song Contest, Christos Mastoras and Panos Mouzourakis.