Hagen, who police suspect of fabricating the kidnapping to hide his wife's murder, sent a coded message on Friday, which means “I confirm that I will pay”.
“We strongly want to get in touch with the other party. That is why we have taken this initiatives towards them, which we hope will be answered. The police have not been involved in this process,” Hagen's defence lawyer Svein Holden told the VG newspaper, which reported the attempt on Tuesday.
Hagen, who is Norway's 164th richest man with an estimated fortune of 1.9bn kroner (€180m), was arrested on April 28 after police began to suspect that the kidnapping of his wife Anne-Elisabeth Falkevik Hagen in October 2018 had been fabricated.
But on May 8, he was released after a court found the evidence against him was not sufficient to merit keeping him in custody.
VG on Tuesday reported new details of Hagen's contact with the kidnappers, just a day before he is due to meet police for a new interview.
According to the newspaper, police have so far refused to comment on the Hagen's claims to have carried out these negotiations.
According to the newspaper, Hagen communicated with the kidnappers as early as November 2, saying he would send the money within seven days.
But on November 13, he messaged them saying he had problems paying and needed more time.
On both occasions he received a message warning him that if he did not pay quickly, his wife would die.
Then in May, he sent several encrypted emails to the counterparty, who replied in July.
“Tom, are you ready for negotiation now? Do you understand that fucking with us is a mistake,” the message read.
“Anne-Elisabeth Hagen needs medical help. We can only give basic. You are taking a long time. No guarantee for how long she lives.”
According to VG, Hagen transferred €1.3m an in Monero in February, in exchange for a proof of life, but appears to have received no proof of any kind.
The newspaper reported that the note found at the couple's house when Hagen's wife Anne-Elisabeth Hagen disappeared on October 31, written in broken Norwegian, demanded that he pay €9m in the cryptocurrency Monero.
The note also contained a list of amounts of Bitcoin, which if paid would serve as a codes indicating various answers.
Police believe that Anne-Elisabeth Hagen was murdered due to long-running difficulties in the couple's marriage, and that Hagen worked with another party to stage the kidnapping.
The couple's children deny that there were any problems in the marriage.
A man in his 30s has also been arrested and charged in the case.