Norwegian authorities say they have detained a Russian citizen on suspicion of illegal intelligence activities.

The Norwegian News Agency (NTB) reported on September 23 that the man was detained at Gardermoen airport outside the capital, Oslo, on September 21.

NTB said the man, whose name has not been disclosed, was placed in custody after a hearing at Oslo district court on September 22.

He would be held for two weeks due to the risk of destruction of evidence, NTB quoted a spokesman for the Norwegian Police Security Service as saying.

The man is suspected of conducting illegal intelligence work after attending a seminar on digitalization at the Norwegian parliament.

In December, Russia said it had detained a Norwegian man on suspicion of spying after he allegedly received classified documents from a Russian man who is also under arrest.

Russia has imprisoned several people from neighboring countries including Estonia, Lithuania, and Ukraine on espionage charges, with tension rising over Moscow's seizure of Crimea in 2014 and involvement in a war against Kyiv's forces in eastern Ukraine.

Kremlin critics say Russia uses spy claims as a tool in geopolitical competition.

Based on reporting by NTB, Reuters, and Bloomberg