The car and the truck are believed to have collided at very high speed on road 225 north of Nynäshamn at half past five in the morning.
I can confirm that one person has died. The other person was taken to hospital but is not believed to be seriously injured, says Nadja Norton, press spokesperson for the Stockholm police.
The relatives of the deceased have been notified.
The circumstances surrounding the accident are unclear, we do not know what it will result in yet, says Nadja Norton.
Road 225 was still completely closed at 2 pm.