Five of the six, including Vatuvei, Matulino and Thompson, told club boss Jim Doyle they had mixed prescription drugs with energy drinks during a night out in Auckland. The sixth player, centre Konrad Hurrell, denied he had done the same.
Hayton spoke to Radio Sport's Kent Johns today and confirmed Kearney and the selection panel made its decision after the Warriors contacted them with the information.
The Kiwis had previously had the same problem with several players in the failed 2013 World Cup campaign in the United Kingdom.
"It was an issue that came up after the (2013) World Cup. We have a stance that we've taken on this and so based on the information we had from the Warriors the decision was taken not to select those players," said Hayton.
"It wasn't just Stephen's decision. It was the selection panel.
"The Warriors kept us informed. They're aware of the issues we had back after the World Cup so it was a two-way dialogue (and) the decision was made not to select them.
"It's not just a rugby league issue. It's an issue that's across professional sport. The NRL has set up processes around testing on that and obviously with the guys coming into play test matches, they're subject to testing there as well.
"But this particular issue involves Warriors players and the Warriors are dealing with the issue."
Hayton would not comment on whether the Kiwi trio had now blown their chance to ever represent their country again.
"I can't answer that question," he said.
"If the players have made a mistake, and they acknowledge that and they work through their issues, just like we all like to be given a second chance in life when we make mistakes, they're entitled to an opportunity again. When that will arise, that will be down to the coach and selection panel to decide."
