: "Joe is in Mykonos now on a boat and he's like, 'This YouTuber thinks he can beat me?'
"He's like, 'Tell him I'll bet him a million pounds. I'll bet him a million and BJ a million, winner takes all'.
"He's deadly serious. He said get me a escrow account and I'll transfer the money now.
"I'm like, 'Relax man, just enjoy Mykonos'. And he's like, 'No, seriously get me set up and I'll fight'."
Fournier turned pro in 2015 after competing in White Collar fights, but he has not boxed since 2016 having been hit with an 18-month doping ban in 2017.
Paul beat social media rival AnEsonGib in Feburary and faces former NBA star Nate Robinson next month on Mike Tyson's undercard.
Fournier - who once dated Paris Hilton - is ready to cut short his vacation and prepare to fight Paul.
Haye said: "He literally FaceTime'd me earlier and said, 'Make it happen. Tell me where to transfer the money.
"He lives in Mykonos now, he's drinking every night. I don't know why he wants to do this, he's that confident.
"He's like, 'I'll drink every day, I don't care'."
Jake Paul rushed to hospital after Ryan Garcia decks YouTuber in 'Body Shot Challenge'... but was it all fake?