A Norwegian citizen has been arrested on suspicion of attempting to spy for China, a senior security official said in Oslo on Tuesday.
Thomas Blom from Norway's PST domestic intelligence service said the man was detained at Oslo-Gardermoen Airport on Monday upon his return. He was remanded in custody for four weeks.
As the investigation into the suspect was at an early stage, no further details could be provided, Blom said after a hearing in the Norwegian capital.
The man's lawyer, Marius Dietrichson, told the NTB news agency that his client denied being a Chinese agent.
The PST sees China as posing an increasing intelligence threat to Norway.
This is mainly due to its deteriorating relationship with the West and Beijing's desire for greater control over supply chains and strategic positioning in the Arctic.