“Joshua French is going to be set free,” Mwamba told Norway's state broadcaster NRK, explaining that the release could occur within weeks, a few months, and at the very latest by the end of this year.
French, a former soldier in the Norwegian army was arrested in Congo in May 2009 along with his friend and business partner Tjostolv Moland, after their driver Abedi Kasongo was found murdered.
In August 2013, Moland was found dead in his cell. Local police at first ruled that he had taken his own life, but later changed their mind, accusing French of murdering him. In 2014, was French sentenced to life imprisonment for his friend's murder.
Norwegian Foreign Minister Børge Brende treated Mwamba's claims with caution.
“Positive signals from Congo's Justice Minister. The Foreign Ministry is continuing its work,” he tweeted. “This is a challenging case, which is not resolved until Joshua French is out of Congo.”
Joshua French's lawyer Hans Marius Graasvold told the Nettavisen newspaper that he was “not popping the corks of the champagne yet”.
“I have the same attitude to this as to the messages we've received in the past that the situation is now about to resolve itself. This has happened several times and it hasn't happened. We've been through this so many times now that I think we just have to wait and see.”
In a blog posted on Monday, Kari Hilde French, French's mother, stressed that nothing concrete had yet happened.
“Joshua is still neither pardoned, transferred to Norway, nor out of prison. We hope the course that it will happen someday,” she wrote. “Neither I, his lawyer Graasvold, nor the Foreign Ministry have been informed by the Congolese authorities about what is on NRK today.”