OSLO, Oct 25 (Reuters) - 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 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. The suspect was involved in a research group that worked with Norwegian government agencies on "hybrid threats" linked to "Arctic Norway", Moe said. NATO-member Norway borders Russia in the Arctic and has ramped up security in the wake of Moscow's February invasion of Ukraine.

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