"The way I say it, there's a lot pointing to the plane coming from Russia," Jan Mörtberg, colonel at the Swedish National Defence College, told newspaper Dagens Nyheter (DN).
On Tuesday the public got wind of documents stating that two unknown aircraft entered Swedish airspace on Midsummer's Eve, June 20th.
Fourteen countries had aircraft and vessles in the area engaging in a Nato exercise, Baltops, but Russia was not included this year.
Latvia did participate in the practice, and the Latvian armed forces have now revealed that 15 Russian jets were identified outside the country's border that day.
"If Russia is behind the violations it confirms a paradigm shift," Mörtberg said. "We see a negative development here, serious behaviour giving us reason to worry."
But Foreign Minister Carl Bildt slammed the claims, writing to DN on Twitter that the information was quite simply incorrect.
"That is wrong," the minister wrote. "The plane was from Poland and by all evidence it was a simple mistake. It's nothing to make a big deal out of."
Bildt did not explain how he knew the planes were from Poland, maintaining the foreign department's relative silence on the issue.
However, he wrote on his blog that there has been no increase in airspace violations over the past few years – and that he has not noticed any organized violations against Sweden.
"If that was the case, of course it would be taken seriously."