The year-long oversight that included both Slovenian and foreign experts found that those in charge tolerated irregularities at the children's heart surgery department for years, according to Medical Chamber president Andrej Možina.

David Mishaly, who operated on children with congenital heart disease in UKC Ljubljana, was in Ljubljana only three to six days a month and the patients did not receive appropriate surgical care.

The surgical programme failed to meet international standards, the oversight found. It also labelled as unacceptable the quality of care and professional relations, data collection, access to data on the number of surgeries and the willingness of surgeons for additional counsel.

The report deemed relations among the medical personnel as very poor, according to Medical Chamber vice-president Valentin Sojar.

Moreover, the data on the number of surgical procedures is unreliable, as various sources state different figures, the report found. Some 15% of the documentation is missing, said Možina.

The chamber demanded that the Health Ministry investigate the missing surgical documentation. Health Minister Milojka Kolar Celarc said the ministry would demand that UKC hand over the documents in a response to the report.

The report notes however that the number of surgeries performed in Ljubljana was relatively low (less than 100) compared to those performed at similar hospitals around the globe.

The document also mentions suspicious patient deaths. The UKC has stated in its own report a mortality rate of 1.8%, while the data collected by the oversight shows a 2.9% mortality.

Možina confirmed for the press today that the police had already requested to see the report, which also examined four patient deaths in 2012. The findings will also be reviewed by several bodies of the Medical Chamber.

The report moreover found systemic flaws in the training programme for paediatric cardiac surgeons and recommends its review.

The minister said today that she would consult the Medical Council, an advisory body to the government, on how to organise paediatric cardiac surgery in the future.

The oversight, headed by Igor Gregorič, an acclaimed thoracic and cardiac surgeon working in Houston, was conducted by a group of specialists - two Slovenian paediatricians and two Dutch surgeons.

UKC Ljubljana said in a response that the report gave the impression of being biased in the part that talks about the responsibility of the hospital heads.

Out of a total of 20 people who have been in charge between 2007 and 2014, the oversight commission only talked to two people, UKC Ljubljana said in a press release.

They interviewed the medical director of UKC Ljubljana and the then medical director of the children's hospital, although the paediatrics cardiac surgery was a programme of the surgical clinic, the press release says.

"The programme produced results, which were later interpreted and accepted in different ways," the hospital said, adding that an overhaul of the programme was launched in 2013 following a clash among experts.