COPENHAGEN, Denmark (AP) — A prosecutor with Norway’s domestic security agency on Friday gave a Russian name for the man who entered the country as a Brazilian but is suspected of spying state secrets for Russia.

Thomas Blom of Norway’s Security Service said the man’s name was Mikhail Mikushin, adding authorities were “not positively sure of his identity, but we are quite certain that he is not Brazilian.”

The man was detained Monday in the Arctic city of Tromsoe, where he worked at the Arctic University of Norway. Norwegian media have said he called himself Jose Assis Giammaria. Norwegian authorities said he was 44, born in Russia in 1978.

Blom told a press conference that the suspect faces a “temporary” charge of spying and that preliminary charge could change as the investigation into the case had just begun. If found guilty of violating Norway’s espionage laws, the man faces up to three years in jail. At first he was arrested in view of expelling him.

“There is an imminent danger of tampering with evidence,” Blom said, explaining why the suspect was detained for four weeks.

On Friday, his lawyer in Oslo, Marijana Lozic, told Norwegian news agency NTB that the man denies any wrongdoing.

“Our view is that, just gaining access to some of these research environments, which are premise providers for the authorities, for policy formulation, is of significant national importance,” Blom said of the suspect.

The university rector told Norwegian broadcaster NRK that to his knowledge no data has been stolen or information had been taken “that could damage our research.” However, “it could undermine the legitimacy of our professional environment,” said Dag Rune Olsen.

The suspect arrived in Norway in 2021, and has researched the northern regions and hybrid threats, Norwegian media said. Norway’s Arctic border with Russia is 198 kilometers (123 miles) long.

In Canada, where the man also studied, he identified himself as Jose Assis Giammaria, according to Canadian Press.

The news agency said the University of Calgary had reported that the man also attended the Alberta school and graduated in the fall of 2018 with a master of strategic studies.

Canadian Press also said a 2015 convocation program from Ottawa’s Carleton University shows Giammaria had graduated with a honors bachelor of arts in political science with a concentration in international relations.