Police armed with machine guns stormed the building where the man was located on Friday afternoon, newspaper Dagbladet reports.
"I can confirm that the police intelligence service, PST, has arrested somebody. The person in question faces serious charges,” PST spokesman Trond Hugubakken told the newspaper.
Oslo district court on Monday ordered for the man to be held in custody until July 2nd.
The suspect’s lawyer confirmed the arrest.
”Our client has been charged with having made death threats against his stepfather, a well-known Norwegian politician – and Prime Minister Jens Stoltenberg,” said lawyer Oscar Oscar Ihlebæk.
Amid a turbulent period in his life, the suspect fled Norway for China, where has lived for the last year, Dagbladet reports.
”I’ve been in contact with the man since January,” said Ihlebæk. ”He came back to Norway last Friday. We had a three-hour long meeting at my office. A few hours later he was arrested by the police.”
While the man was already known to the police, it was not until last autumn that the intelligence service began monitoring him more closely.
Along with the murder threats, prosecutor Anne Karoline Bakken Staff has also charged the suspect with a number of other criminal offences in a 12-page indictment.
The man is believed to have issued the threats by means of correspondence from abroad. Norwegian police put out an international warrant for his arrest last autumn.
According to Ihlebæk, the death threats were politically motivated.
”It has to do with interpersonal factors as well as having a political background,” the lawyer told Dagbladet.
The suspect’s step-father and the Prime Minister declined to comment on the man's arrest.