A woman has died after the accident last week when a car drove into Stångån in Linköping, the police write on their website.
The case is now classified as causing another person's death, but there is no suspect in the case.
A young girl is still being treated in hospital with serious injuries and an investigation into causing bodily harm is ongoing.
A man and a young boy were also involved in the accident and sustained minor injuries.
The cause of the accident is still unclear.
We must wait for the technical investigation to get some clarity on the event. The car was seized when it was pulled out of the river, says the police's press spokesperson Angelica Israelsson Silfver.
Relatives have been informed of the death.