The newly signed Toronto Wolfpack star says he believes in standing up for what is right and often feels embarrassed for not speaking up more as a sportsman.

"They (the Uyghur community) are in the detention camps over there and facing disgusting injustices," Williams told Sky News on Sunday.

"For myself, I just speak my truth. Sometimes I get it wrong but in this instance I definitely know I'm not. Sometimes you can speak your truth, whether that can get you offside with people or not.

"But I've always been one to stand up, not just for myself, but for what I feel is right - and in that situation, that's all it was."

Former All Black and NRL star Williams, who converted to Islam in 2009, joined Arsenal star Mesut Ozil by tweeting his support of the Uyghur community last year.

"It's a sad time when we choose economic benefits over humanity #Uyghurs," Williams wrote in December, accompanied by an image illustrating oppression against the Muslim minority group.

China's state broadcaster removed the English Premier League match between Arsenal and Manchester City from its programming in response to German midfielder's Ozil's defence of the Uyghurs.

The Arsenal playmaker was then also removed from a Chinese-produced soccer computer game.

But the 34-year-old Williams, who made his debut for Toronto against Castleford on Sunday, says he's unconcerned about any backlash.

"When it comes to that situation of being able to speak up as a sportsman, I'm almost embarrassed to say that I don't speak up enough.

"That's not just as a Muslim, but that's as a human as well. You know, there's many atrocities going on around the world that you know you can't even fathom. So here we are, and we are just trying our best."

Australian Associated Press