Jack de Belin stood down by NRL after Sam Burgess backs player behaviour as "good as it's been".

— With AAP.

Jack de Belin has been stood down after the ARL Commission announced controversial changes to its behavioural policy on Thursday.

St George Illawarra forward de Belin, who has pleaded not guilty to aggravated sexual assault, has been sidelined from the NRL indefinitely.

He will be allowed to train with the Dragons but will be unavailable to play NRL and representative football.

ARLC chairman Peter Beattie and NRL chief executive Todd Greenberg announced the changes, which allow the game to stand down players charged with serious crimes, following a momentous meeting of the independent commission at Rugby League Central.

Under the previous policy, players were allowed to continue playing while their court case runs its course.

The rules allow players facing charges which carry a jail term of 11 years or more to be stood down.

BREAKING: The #NRL Commission has announced that it will stand down players facing serious indictable offences on full pay while they are before the courts, including Dragons Jack de Belin. https://t.co/BPxkZURizD

— ABC Grandstand (@abcgrandstand) February 28, 2019

The NRL chief executive also has the discretion to stand down players facing other serious charges, including violence against women and children.

The game was under pressure from broadcasters and sponsors to protect its image after an off-season which has been derailed by poor behaviour and a string of controversies.

“Whatever decision we made today would have been controversial,” Beattie said.

“This is not about being popular, this is about doing the right thing by rugby league. This is also about sending a clear message that the game doesn’t tolerate violence.”

The policy change has been strenuously opposed by the Rugby League Players Association which says it will prejudice the players’ right to a fair trial.

It opens the door for players to sue to the NRL with the players’ union understood to be ready to support any player who exercises their legal rights.

The Dragons said they would consider the changes made by the game's decision makers and they were concerned for De Belin's welfare.

"I'm very supportive of the desire of the NRL to improve player behaviour and propagate the game of rugby league," Dragons chairman Brian Johnston said.

"What we're dealing with is a very polarising and complex subject regarding Jack de Belin.

"Above all we're being guided by the legal system, the NRL rules and code of conduct. And above all we're very concerned about the welfare of Jack de Belin. That's our priority."

The decision comes just hours after South Sydney captain Sam Burgess declared that the behaviour of NRL players is "as good as it's been".

Speaking at the Fox League launch, Burgess said that NRL players have a "responsibility to grow the game".

"There's been some terrible coverage in the press but player behaviour is probably as good as it's been over the years," he said.

"It's just more reported on, things catch fire a lot quicker. For all the negative press, there's some fantastic role models and great players."

In recent months, the NRL have dealt with a number of serious off-season controversies.

Besides Jack de Belin, Dylan Walker and Jarryd Hayne have also been dealt serious charges.