Ottio, who signed for the Raiders in February 2016, passed away after developing a sudden health issue while training.

The 23-year-old, who represented Papua New Guinea in the 2017 World Cup, was set to join Widnes Vikings in Super League this season.

James Rule, CEO of Widnes Vikings, said in a statement: “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.  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.

"Having only learned this morning that Kato had developed a sudden health issue whilst training yesterday, we are in absolute shock to now receive this tragic news. We will be liaising closely with his loved ones to offer them our condolences and support at this difficult time.

"Widnes Vikings will of course be looking to celebrate Kato’s life and pay our sincere respects to someone who we believe would have become a hero at our Club. Whilst we are coming to terms with this news, and still learning the full facts of this situation, we are unable to comment further at this time.”

Ottio was born and raised in the village of Tatana, near Port Moresby. He joined the PNG Hunters in the Queensland Cup in 2015.

A number of NRL players have expressed their sorrow at his tragic death.

Canberra five-eighth Blake Austin posted on Instagram: "Shattered to hear the news about katsy. Wasn’t a day he wasn’t smiling, gone way too soon. Prayers with all his family."