A Norwegian court ruled Thursday that a Russian citizen who is suspected of spying in Norway should be released, but that he had to remain in detention while awaiting a decision on an appeal filed by police, local media reported.

Mikhail Bochkarev, 51, was arrested on Sept. 21 at Oslo airport and charged with a breach of section 121 of the Criminal Code that includes illegal intelligence activities against state secrets.

Bochkarev had attended an international seminar on digitalization at the Norwegian parliament. The seminar was organized by the European Center for Parliamentary Research and Documentation (ECPRD) and was attended by 79 administrative staff members in parliaments from more than 30 countries.

The behavior of Bochkarev, identified as a staff employee of the Russian parliament, aroused the suspicion of Norwegian parliamentary employees, public broadcaster NRK reported in September.

However, according to the Oslo District Court, there is no longer any reason to suspect the Russian for espionage.

But the Norwegian Police Security Service (PST) has appealed the decision and Bochkarev will thus remain in custody over the weekend in anticipation of the appeal, newspaper Aftenposten reported.

"We believe there are grounds for suspicion," police attorney Kathrine Tonstad told Aftenposten.

Bochkarev's lawyer Hege Aakre said her client "is very pleased and he is hopeful" for the decision to be maintained in the appeal court.

"The whole thing is absurd," Bochkarev told Aftenposten, adding he planned to return to Moscow on Monday should the court decision be upheld.

Tonstad confirmed that Bochkarev is free to leave Norway if the decision is supported by the court of appeal.