The Russian Foreign Ministry summoned Norway's ambassador to Moscow on Monday, three days after a Russian national was arrested in Oslo on suspicion of espionage. At the same time, security services swept the Norwegian parliament building (pictured above) in the capital for surveillance devices.

"We demanded ... the immediate lifting of the absurd charges, and his release," Moscow's Foreign Ministry said, giving the name of the detained man as M.A. Bochkarev.

The Kremlin said that the man's arrest was a clear case of "a wave of spy mania around Russia," and promised that "such steps will entail consequences."

Bochkarev, 51, was ostensibly in Oslo to attend a conference about strengthening cooperation between European parliaments. He was detained at Oslo airport on Friday due to "suspicious behavior."

The man's lawyer, Hege Aakre, told national news agency NTB that her client is being held for two weeks of pre-trial detention, and that he denies any wrongdoing. On Monday, he was questioned by Norway's domestic security service (PST).

The pre-trial detention was reportedly ordered because authorities were worried Bochkarev may destroy evidence.

Through his lawyer, Bochkarev has said he is the victim of a misunderstanding and that there is an innocent explanation for his behavior.

Parliament searched

A spokesman for the PST told the online newspaper Aldrimer that the parliament building had to be searched for bugs over fears that the man had tried to hack into the cell phones of other conference participants. He did not clarify if they had found anything.

According to Norwegian media, the man was a senior IT adviser for Russia's legislature. He was brought to the authorities' attention by parliamentary officials who had noticed his strange conduct over the two-day conference.

Prime Minister Erna Solberg, who was in New York for a meeting of the UN General Assembly, said that it was "a police matter," not a political one.

es/kms (AP, dpa, Reuters)