A Royal Navy sailor found dead at a Swedish residence prompted an investigation.
According to the prosecutor, four people were arrested, including a British man aged 20. They have since been released.
Two men and a woman, all of Swedish descent, were also arrested.
A Royal Navy spokesperson stated: “We’re aware of an incident that occurred in Stockholm and resulted in a death.”
“We continue to support local authorities with their inquiries, and further comment would be inappropriate.”
Our thoughts and sympathy go out to family and friends.
The next of kin has been notified.
The Royal Navy participated in an exercise called Aurora where they defended the coastline of Sweden. The drill took place between 17 April and 11 May.
HMS Albion led the exercise which included forces from France and Germany as well as Estonia, Finland and Latvia, Latvia, Lithuania and the UK.
Exercise Aurora was the largest Swedish national defense exercise in over a quarter century.