The Swedish security service (Sapo) on Monday announced the arrest, but gave no details about the case or the suspect’s identity.

The following day, broadcaster SVT said the man arrested was a top diplomat.

On Wednesday, prosecutors released him from custody but said that he was still a suspect.

“We regret to confirm that a member of the foreign service has died. Out of consideration for the next of kin, we will not go into further details,” the foreign ministry said in a statement to AFP today.

Newspaper Expressen meanwhile reported that the man who had been found dead overnight was the one detained suspected of spying.

Anton Strand, the suspect’s lawyer, told AFP this week that his client denied the allegations against him and maintained “that he has done nothing wrong”.

Strand also said his client had gone to a hospital after being released Wednesday and reported police for using excessive force during his arrest, but did not provide details about the extent of the injuries.

SVT also reported this week that Sapo was investigating whether the case was connected to a scandal that hit Swedish national security adviser Tobias Thyberg.

He resigned within hours of his May 8 appointment after “sensitive” photos of him from dating app Grindr were sent anonymously to media and the government.

SVT, which has not specified its sources, said the diplomat arrested was not Thyberg, who served as Sweden’s ambassador to Ukraine and Afghanistan among other positions over a 24-year career.