Swedish Director of Public Prosecution Mikael Bjork speaks at a news conference, during the announcement of the resumption of a crime investigation against former Karolinska Institute surgeon, Paolo Macchiarini, in Stockholm, Sweden December 11, 2018 TT News Agency/Marc Femenia via REUTERS

STOCKHOLM (Reuters) - Swedish prosecutors said they would reopen a criminal negligence investigation against an Italian surgeon in connection with the deaths of three patients at a hospital linked to the institute that awards the Nobel Prize for medicine.

A previous inquiry against Paolo Macchiarini ended in 2017 without charges, with prosecutors saying they found no legal evidence he caused the death of the three patients from experimental surgery.

Macchiarini, who denied any negligence in his transplant of synthetic tracheas into the three patients in 2011-12, was fired from Karolinska Hospital in March 2016.

But the 2017 decision was appealed and Prosecutor Mikael Bjork said on Wednesday that because relevant law was not clear, he would reopen the case regarding two of the patients.

“I draw different legal conclusions than previous prosecutors,” he said in a statement.

The investigation sparked controversy concerning the Karolinska Institute, which awards the Nobel Prize for medicine. The Swedish government dismissed the institute’s board in 2016 after an investigation found negligence in the decision of Karolinska Hospital to hire Macchiarini.

Macchiarini’s lawyer Bjorn Hurtig could not be reached for comment despite repeated attempts.