The revelations are published in the second volume of Bomann-Larsen's history of King Haakon and Queen Maud, which is due to be launched today. The book, entitled "Folket" (The People), is published by Cappelen.
Bomann-Larsen argues that Queen Maud's personal physician Sir Francis Laking was Olav's biological father, and investigates a secret hospital stay in London by the queen in October 1902.
The book contains a photograph of Laking's son Guy Francis Laking, born in 1875, who bears a striking resemblance to the adult King Olav. Bomann-Larsen also raises the possibility that Laking's son was a possible sperm donor for Queen Maud, and that Olav was the result of artificial insemination.
The author does not draw any final conclusions, but bases his arguments on a range of sources from state archives and European royal records.
"This is a sensation that must shake us all," said professor and historian Hans Fredrik Dahl, who now believes the relationship between King Haakon and son Olav must now be re-examined.
Reigning King Harald - son of Olav - said that he had no information to indicate that King Olav was not King Haakon's son, according to a palace press release.
"Each author is fully entitled to present his interpretation of history. This also applies, of course, to Tor Bomann-Larsen's biography of King Haakon and Queen Maud," King Harald said in the release.
