A Swedish diplomat who was recently questioned by police on suspicion of espionage has died, the man’s lawyer said on Friday.

The man was detained by Sweden’s SAPO security service on Sunday and held for questioning until Wednesday. He was later released but remains under investigation, according to the country’s prosecution service.

“I heard the tragic news this morning and my thoughts go to his family,” his lawyer, Anton Strand, told Reuters.

Strand declined to comment on the cause of the man’s death.

Police told daily Svenska Dagbladet they had opened an investigation into the death, but “there is no suspicion a crime has been committed.”

The man had denied any wrongdoing and had made a complaint against the police over the handling of the case, Strand said.

He also sought medical help after his release from custody.

Reports from public broadcaster SVT suggest that the diplomat had worked at various Swedish embassies and that SAPO is looking into a possible link to the recent resignation of the government’s national security adviser.

Sweden’s foreign ministry confirmed that one of its employees had died but declined to comment further.

In a statement to Reuters, the ministry confirmed the death of a foreign service employee, stating, “We can regretfully confirm that an employee of the foreign service has passed away. Out of concern for the relatives we will refrain from giving further detail.”