"We don't know what happened, but the parachute didn't open," said Lourenço Gorricha at Nazaré police to the Expressen daily.
Gorricha told the newspaper that the 29-year-old Swede had jumped from around 100 metres and landed on the rocks below.
"He showed no signs of life when we got to him," Gorricha said.
The Swede travelled to Portugal together with some Norwegian friends to pursue his passion for base jumping - an activity where participants leap from fixed objects such as buildings and bridges using parachutes to break their fall.
The tragic accident was witnessed by his travel companions and they were given help from psychologists after their friend's fall.
Nazaré in central Portugal is a popular spot for base jumping although according to Lourenço Gorricha this is the first time there has been a death in the sport.
The Swede is reported to have been a very experienced base jumper with over 300 jumps as a member of the Norwegian Tönsberg parachute club.
"He was a very positive human being, a fantastic person," said club chairman Jon Martin Engebretsen to Expressen.
The 29-year-old's family has been informed about the accident.
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