The 47-year-old Behn had hit the headlines when, in an December 2017 interview, he had recounted an incident with Kevin Spacey when the actor hosted a Nobel Prize concert.
"I have a little #MeToo story about Kevin Spacey. We were having a nice chat where we spoke about theater and drama, and the little theater, the Wick, a theater in London. We had a good conversation sitting beside each other," Behn had said, reports variety.com.
"After five minutes he said 'Hey, let's go out and have a cigarette,' then he grabbed me under the table right in the b***s."
Spacey, who has been accusing of assaulting several men, did not respond at the time of the allegation.
Behn is the third Spacey accuser to die this year, following whistleblower Linda Culkin and the anonymous massage therapist who accused Spacey of sexual assault in an October 2016 session.
After his suicide, Behn's family spokesman Geir Hakonsund said in a statement: "It is with great sadness in our hearts that we, the very closest relatives of Ari Behn, must announce that he took his own life today. We ask for respect for our privacy in the time to come."
Behn married princess Martha Louise in 2002 and the couple announced separation in 2016. The divorce was finalised in 2017. He is now survived by his three children with princess Martha Louise.
Norway's King Harald V and Queen Sonja released a statement on Wednesday, calling Behn "an important part of our family for many years, and we carry warm, fond memories of him. We are grateful that we got to know him. We grieve that our grandchildren have now lost their beloved father - and have deep compassion for his parents and siblings, who have now lost their beloved son and brother."
Behn was born in Denmark in 1972. Behn earned his bachelor's degree in history from the University of Oslo. He published his first collection of short stories "Trist som faen", which translates to "Sad as Hell" to good reviews.
( With inputs from IANS )