Cape Town - All Blacks superstar Sonny Bill Williams secretly lent more than half a million dollars to his friend, Australian boxer Anthony Mundine, to deal with a family emergency.
The A$500 000 (R5.07m) loan came just before Mundine's recent fight against fellow Australian Danny Green, The Sunday Telegraph in Sydney reported.
There was no written agreement, just a handshake, the newspaper said.
According to the Stuff website, it was the return of a favour, as Mundine gave Williams A$750 000 (R7.6m) in 2008 when Williams went to play rugby in France, leaving the Canterbury Bulldogs rugby league team.
"It's very hard to explain our brotherhood in words," Mundine said. "I didn't understand it until I became a Muslim. We trust and we love each other.
?"We'd literally die for each other. It's all about being there for each other."
Green controversially won the fight to retain his Australian cruiserweight title, with both boxers set to make A$4m (R40.6m) each from the bout.
"I'll pay him back as soon as I get paid next week," Mundine said.
Williams is still recovering from an Achilles injury which he sustained at last year's Rio Olympics.
Once he's passed fit, he will play for the Blues in this year's Super Rugby tournament and is expected to feature in mid-year when the All Blacks welcome the British & Irish Lions to New Zealand.