In a statement, police said they had made the decision to make the case public despite threats from the kidnappers, in order to appeal for more information.
The house (C) of Norwegian real estate investor Tom Hagen and his wife Anne-Elisabeth Falkevik Hagen, who according to the authorities is suspected to have been kidnapped, in Fjellhamar, Norway, Jan. 9, 2019. "Police have so far advised the family not to meet the requirements".
As a result, investigators on the case are still left with "no suspects", despite having assistance from Interpol and Europol, and have Hagen's wealth behind them.
Norwegian tabloid Verdens Gang, quoting unnamed sources, reported that a demand for ransom corresponding to 9 million euros (US $10 million) had been made, payable in the Monero cryptocurrency. Since then, police had received "more than 100 tips", Broeske said, adding "several seems to be interesting" without elaborating.
According to local newspaper VG, 68-year old Anne-Elisabeth Falkevik Hagen, the wife of Norwegian businessman Tom Hagen, has been missing for ten weeks, since October 31st of last year.
Hagen is number 172 on a list of Norway's wealthiest people published by the financial magazine Kapital, with a fortune estimated to be almost 1.7 billion kroner ($200 million) in 2018.
Svein Holden, Hagen's lawyer, told reporters the abduction was "a cruel and an inhuman act".
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The wife of a Norwegian multi-millionaire has disappeared in a suspected kidnapping and her family has received a ransom demand to be paid in cryptocurrency.
Brøske noted police have received no proof that Hagen is alive, "but we haven't received any indication that she isn't alive either".
"Our goal is to find the woman alive and reunite her with the family", Mr Broske said.
He owns 70 per cent of electricity company Elkraft which he co-founded in 1992, Norwegian media reported.
NRK says the couple live a "secluded lifestyle" in Lorenskog, east of Oslo, describing Tom Hagen as "media-shy and private".
The police have been working on this case for a long duration as one of their top secret operations.