At centre, a view of the home of Norwegian billionaire Tom Hagen and his wife Anne-Elisabeth Falkevik Hagen in Fjellhamar, Norway. Picture: Tore Meek, NTB scanpix via AP

Stockholm - Norwegian police said Monday a new message has been sent by the suspected abductors of the wife of one of Norway's wealthiest businessmen.

"It was addressed to the family and sent to their attorney and the police," police inspector Tommy Broske told reporters.

He declined to say when the message was sent or what it said.

Anne-Elisabeth Falkevik Hagen, 68, went missing from her Lorenskog home in Akershus county, near Oslo, on October 31.

Broske said police were "concerned that there was no proof of life," but noted that the suspected kidnappers had used a different means of communication than previously.

The family's attorney Svein Holden said last month that a message was sent on January 16.

When Holden made the announcement, he said the family wanted to get in touch with the sender via "a better" means of communication.

The disappearance was not made public until January 9 due to a threatening note left at Hagen's home.

Tom Hagen is an investor with business interests in power generation and real estate, estimated to be worth 1.7 billion kroner (200 million dollars), according to financial site Kapital.

Police have confirmed a ransom demand and payment request in a cryptocurrency, making it difficult to trace.