Norwegian police on Monday arrested a suspected Russian spy in the Arctic town of Tromsoe, the PST security service said on Tuesday, describing him as a rare illegal agent.
The man, who worked as a scientist at the University of Tromsoe, had posed as a Brazilian citizen but police believe his real identity to be Russian.
The news was first reported by Norwegian broadcaster NRK.
The man represents a "threat to fundamental national interests" and should be expelled from Norway, deputy PST chief Hedvig Moe told Reuters, describing him as an "illegal agent."
An illegal agent is an intelligence operative without official government links who assumes a covert persona, often using a real, dead person's identity.
"Typically illegal agents are talent scouts recruiting agents for later, and preparing the ground for other spies to do traditional intelligence work," said Moe.
"Typically illegal agents are talent scouts recruiting agents for later, and preparing the ground for other spies to do traditional intelligence work."
deputy PST chief Hedvig Moe
The accused man's lawyer did not return a request for comment.
Alleged spy involved in "hybrid threats" research group
The suspect was involved in a research group that worked with Norwegian government agencies on "hybrid threats" linked to "Arctic Norway," Moe said, declining to give specifics.
NATO-member Norway borders Russia in the Arctic and has ramped up security in the wake of Moscow's February invasion of Ukraine.
The man was arrested on Monday, Moe said, declining to say whether a specific event precipitated the decision. "It was the right point to stop the activity he was involved in," she said.
The suspect had previously been in Canada, she said, and his arrest was made possible with the collaboration of "several" international security services, declining to say from which countries.
"It is a long-term project to have an illegal agent," said Moe. It costs a lot of money. Major state actors only use them and it is known Russia has used them in the past."