Todd Greenberg, the NRL chief executive, said the integrity unit probe found "there was a physical altercation between the player and his partner".
However, it all appears to have come undone for Barba, who will not be able to resume his career in the English Super League, where he was crowned Man of Steel for his time with St Helens in 2018.
"His registration with the game is no longer and I can't see a time, at any time in the future that he'll be welcome back", Greenberg said.
Barba had his Cowboys contract torn up on Friday and was subsequently deregistered by the NRL after the club were made aware of the incident at Townsville Casino on Australia Day. "It's time for Ben Barba to find a new vocation", Greenberg said.
"I'm not going to call for (a worldwide ban) but there's no place for him (in Australia)".
The incident is being investigated by Queensland police and Barba looks likely to be banned for life by the NRL.
With Castle's refusal to register a player with Barba's record, the former Cowboys fullback will have limited opportunities to continue a professional sporting career.
Speaking to media today, Greenberg stated that the league will be showing an increasingly tougher stance towards players who commit serious public offences, particularly those regarding violence against women.
The North Queensland recruit and one-time Dally M Medal victor is facing a life ban from the NRL, a move that would also be supported by the English Super League, effectively ending his rugby league career at the age of 29.
"It's a very clear message for a lot of guys in our sport that it a great privilege to play rugby league, to put a jersey on, to earn a significant incomes which they deserve as footballers, but it comes with real responsibility".
"I can't see a time at any time in the future when he'll be welcomed back."
"I would expect anything in relation to a situation like that, that would stand, because when you're talking about issues at that level, we need to make sure the codes are supporting each other on that".
The 29-year-old was already on his last chance after being forced out of the NRL in 2016 after recording his second illicit drugs strike following Cronulla's grand final win.