“I was offered drugs and I used them. It was naturally a terrible error that is now harming far too many people,” he said.
The former hurdler, 44, was arrested on Sunday after a widely reported wild night on the tiles in Gothenburg. Two other athletes were arrested with him, all suspected of using the drug.
Speaking to TV4 reporter Patrik Ekwall on Tuesday, Nylander said that he had taken the drug on several occasions.
Patrik Sjöberg, one of the other athletes arrested, admitted on Monday that he had used drugs.
All the members of the group are suspected of minor drugs crimes. Police said that the drug was found in such small quantities that they were not expected to face prison sentences.
Nylander retired from athletics in 1997. He holds the Nordic record for the 400 metre hurdles.