According to media reports, the 15-year-old male suspected of strangling 77-year-old Else Johannesen in her Lemvig home used his victim's credit card to purchase a sex toy.
Police allegedly used the purchase on the site sexshop.dk to track down the alleged assailant.
Sexshop.dk's owner, Michael Peter Hansen, told TV2 News that he was contacted by police on Monday morning after they traced a purchase made with Johannesen's credit card to the online sex shop. Hansen said he gave police the IP address associated with the purchase some two hours before police arrested the 15-year-old on Monday.
The 1,839 kroner purchase was for this female torso (NSFW link).
Police would neither confirm nor deny the new information.
Sexshop.dk owner Hansen said the experience left him with a weird feeling.
"It's very strange that after killing someone you would go online and buy a sex toy. We have experienced a lot of things, but this here..." he said to TV2.
The suspect is due to appear in court on Tuesday.