Dung samples collected by the organisation showed that the wolves were both present in the area as recently as last month.
"Both the male and the bitch in the pair have been detected through our analysis," Morten Kjørstad, Rovdata's leader, said in a statement. "We do not know exactly how old the dung is, but we are confident that it is from the month of July, and most likely from the second half of July."
The wolves, named Fenris and Freya in a poll organised by the Norwegian Conservation Society, have found a place in the heart of Oslo's citizens since they were discovered.
On 28 April, when both wolves were photographed by an automatic wildlife camera, the bloated belly of the female led to speculation that she might be pregnant.
However, Kjørstad said Rovdata had so far collected no dung samples that would indicate the presence of puppies.
"It's only the pair that was identified by the recently analyzed dung, so we are still not sure whether any puppies have been born in the Østmarka or not. This probably will not get resolved with any certainty before the snow comes this winter, which makes it possible to track the animals and determine how many wolves are there," he said.
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Below is a video of a wolf in the forest outside Oslo shot at the the end of July, which Rovdata believes to be either be Fenris or Freya.