A female patient died Tuesday at a hospital in south-western Sweden after having been infected with Escherichia coli (EHEC), DPA reported.
The woman, who was in her 50s, had been treated since Sunday at the Sodra Alvsborg Hospital in the town of Boras after a recent visit to Germany, the hospital said.
A man in his 70s was also being treated at the hospital, but his symptoms were described as less serious.
Earlier, the Swedish Institute for Communicable Disease Control said there were 39 known E coli cases countrywide.
Authorities in Denmark on Tuesday said tests conducted on local cucumbers showed no trace of enterohaemorrhagic Escherichia coli (EHEC).
"Nothing suggests that Danish cucumbers were the source of the serious E coli outbreak," the Danish Food and Veterinary Administration said.
The agency again warned the public to refrain from eating cucumbers from Germany and Spain, or tomatoes from northern Germany.
Denmark has 14 confirmed and 12 suspected cases of E coli infection.