Former World Anti-Doping Agency (WADA) director general Harri Syväsalmi believes Norway's skiing team are operating in a "grey area" following failed drugs tests by two of their leading cross country skiers.
Three-time Olympic cross-country skiing medallist Therese Johaug failed a drugs test for banned anabolic steroid clostebol last month, it emerged last week, after claiming to have used the product inadvertently via a sun cream.
Male cross-country star Martin Johnsrud Sundby was also handed a two-month ban and stripped of his 2014-2015 World Cup title earlier this year following two failed tests for asthma medication salbutamol.
The pair were the male and female champions in last season's World Cup series and, despite the mitigating circumstances surrounding both cases, Syväsalmi believes the Norwegian team are operating at the edge of the rules.
"I feel that the Norwegian skiing team are testing the limits," the Finnish official told Verdens Gang.
"It seems that they are operating in a gray area, and sometimes it goes over the limit.
"He was sentenced in the Court of Arbitration for Sport (CAS).
"It was a violation of the doping rules."
Sundby claimed to have received the wrong advice from a doctor on what dosage he should take and was initially cleared of any wrongdoing by an International Ski Federation tribunal, only for WADA to successfully appeal to CAS.
He was consequently banned from July until September 11, with Russian rival Evgeniy Belov claiming the process was deliberately slowed in order to ensure he was only banned during the off-season.
Norwegian team doctor Fredrik Bendiksen has claimed "full responsibility" for the Johaug incident, and no suspension has yet been issued ahead of the World Cup season beginning next month.
Bendiksen has now resigned from his post, the Norwegian Ski Federation confirmed in a latest statement, while Johaug has not joined her national team-mates on a pre-season training camp.
Syväsalmi, who served as WADA's first director general between 2000 and 2003 and is now secretary general of the Finnish Center for Integrity in Sports, still has full confidence in Antidoping Norway to get to the bottom of the matter.
"They are guaranteed the top 10 in the world in anti-doping work," he said.
But he also defended the increasingly sceptical way much of the rest of the world is now viewing the dominant Norwegian team.
"It is natural that others question about Norway when they are so much better than the others," he added.
"Everyone wonders about the methods they use are legal.
"How can they be so much better?"
insidethegames has contacted the Norwegian Ski Federation for a comment.