Prosecutors, police and health minister Katya Ivkova told a briefing that the Plovdiv regional prosecutor's office is investigating an organised crime group. The group is accused of draining the national health fund through fake hospital admissions at the rheumatology clinic of St George University Hospital. Professor Mariela Geneva-Popova, dean of the medical faculty, was also taken in for questioning.

This report follows our earlier story on a police operation at a Plovdiv hospital and a medical university facility, where doctors were detained over suspected fraud against the National Health Insurance Fund through fake hospital admissions.

"Ten people have been detained, six doctors and four nurses," said regional prosecutor Vanya Hristeva. Six of them now face criminal charges, while three remain in custody for up to 72 hours.

The investigation has been running for several months. It started after a tip-off about an unusually high number of admissions at the clinic. The head of the department co-owns a medical centre with his wife and daughter. A relative of his enters referrals from that centre into the system. A fake check-up is logged, and the patient is then admitted to hospital. In total, the centre issued 5,000 referrals for admission to the clinic.

Prosecutors say many of the patients listed as admitted either never came to the clinic at all or only came in for a blood test. They found that orderlies and doctors would take blood on patients' behalf, letting the patient stay no more than two days — just long enough to bill for a full treatment package. Several nurses were also involved.

Doctors who refused to take part in the scheme had their patient quota cut, which hit their pay, prosecutors said. A doctor who stayed out of the scheme earned around 1,500 euros, while those involved took home between 6,000 and 7,000 euros.

"Over three years, the health fund paid the clinic around 12 million euros," said deputy regional prosecutor Dimitar Pehlivanov, who is overseeing the case. Over the same period, the department — which has just 49 beds — billed for 24,000 treatment packages.

Pehlivanov said the findings came from analysing the data and questioning witnesses, including doctors from the clinic. He called the sums paid out by the health fund huge.

A day earlier, teams from the Plovdiv regional prosecutor's office, the Plovdiv police directorate and the health ministry carried out 40 searches in Plovdiv, Karlovo and Krichim. They searched two clinics, two medical centres, and several office and residential buildings.

In another room at the hospital, investigators found expensive drugs for patients that had already expired. It is not yet clear who they were prescribed for. The medicines agency has opened its own check into the case.

Health minister Katya Ivkova said her ministry and its agencies will carry out follow-up checks, including into the expired drugs.