STOCKHOLM—A senior Swedish police officer has been found dead in his home, hours after the release of an internal report that found a conflict of interest regarding decisions he had made about a former employee with whom he had a relationship, police said.

Mats Löfving, the chief of police in the Stockholm region, was found dead in his home in the city of Norrkoping, police said. He was 61.

The cause of death was not immediately clear and police opened an investigation as a matter of standard procedure.

Löfving’s conduct was under review both by an internal audit and a criminal investigation, in a case that shook Sweden’s police leadership and made headlines across the Scandinavian nation.

The probes focused on his relationship with a female employee while he was the head of the police National Operations Department.

The internal investigation on Wednesday found there was a conflict of interest when Löfving made decisions regarding the employee’s salary and position. The investigator said those decisions raised questions about Löfving’s judgement as a manager and suggested that the police leadership consider terminating his employment.

Later Wednesday, police responding to a report of an injured person at Löfving’s home found him dead inside.

“It is incredibly tragic,” Sweden’s chief of police Anders Thornberg said late Wednesday. “My thoughts go to Mats Löfving, his next of kin and work colleagues.”

Prosecutors later said they would drop the investigation into gross misconduct.