Thomas Marot said the Inland Taipan snake supposedly in the Malmo building likely never existed, the TT news agency reported Tuesday.
A note posted at an entrance to the building two months ago said the snake was there.
Marot said $16,000 was spent trying to track down the snake.
Jonas Walstrom of the Skansen animal park in Stockholm said he had doubts about the story from the beginning.
"The Inland Taipan is found in only one place in Sweden and that's at the Skansen vivarium. They are incredibly poisonous so they aren't especially popular as pets," he said.