Super League club, Widnes Vikings, confirmed the sad news.
According to reports Ottio was training in Papua New Guinea with the PNG Hunters when he reportedly collapsed and was taken to Port Moresby Hospital where he later died.
Vikings CEO James Rule said, 'We are devastated to learn that Kato Ottio has passed away this afternoon. Kato was an incredibly talented player, with a bright future ahead of him in rugby league.'
'This news is all the more tragic, because Kato was due to travel to the UK this week to fulfil his dream of playing first-grade rugby league,' Rule continued. 'We had been in regular contact with Kato and were excited to welcome a bright, excited and passionate young man, who had genuine potential for the future.'
'On behalf of the coaching team, staff and players at Widnes Vikings, I would like to offer our sincere condolences to Kato’s loved ones,' he finished.
NRL stars and fans have flooded social media to share their shock at the tragic passing.
Our thoughts are with Ottio's friends and family at this difficult time.
This article originally appeared on New Idea.