The body of a woman was discovered in a cabin aboard Tallink Silja's Baltic Princess cruise ship at Turku harbour on Monday night, according to local police.
Later on Tuesday, police said they do not suspect a crime was a factor in the woman's death. Police said that the woman's cause of death will be investigated.
The woman, who was in her thirties, was found by ship cleaning staff after the Baltic Princess had docked in Turku, south-west Finland, at about 7:15 pm on Monday. Tallink Silja told newspaper Ilta-Sanomat the woman was a Finnish citizen.
Turku police department's Detective Superintendent Jussi Helesvirta said the woman had been accompanied by her husband. According to Helesvirta, he did not notify anyone about her death but instead disembarked the vessel in Turku on his own.
The ship had just arrived from Stockholm and the couple had apparently taken a 23-hour cruise.
Police said they were able to locate the deceased woman's husband at the harbour area and took him into custody, according to Ilta-Sanomat (in Finnish).
The ship was scheduled to depart Turku at 8:15 pm, but the incident caused a 90-minute delay.
Passengers were told the postponement was due to a medical emergency, the cruise line's communications chief Marika Nöjd told the paper (in Finnish).
This story was updated on 17 October, 2018 at 12:09 pm to reflect that the police do not suspect a crime is related to the incident.