Sonny Bill Williams said former coach Steve Folkes was at the centre of his decision to abandon the club to take up a rugby contract with Toulon.

In an extract from Thursday night's interview on Channel Nine's Footy Show, published in News Limited newspapers, Williams said Folkes' questioning of his friendship with boxer Anthony Mundine earlier in the year had angered him.

"I rock up to training and Folkesy, Steve Folkes, someone, that to be honest, has never paid any interest in my personal life, he comes up to me and starts saying: `You're not turning Muslim are you?'," Williams said.

"I just laughed. I said, `Seriously you are joking' and then he has a go at Anthony: `You're kidding yourself if you take advice off him.'

"I start to think, `who is he to question my friends?'"

"Who does he think he is? Does he think he is God? Is he God or something?"

Williams went on to say he simply wasn't happy at the club.

"Obviously to do something like that (leave) I wasn't happy," he said.

"I haven't been happy at the Bulldogs for a while."

Folkes said Williams' comments counted for little.

"He will do anything now to try and justify this decision, regardless," Folkes said.

"It is indefensible.

"I was in the room last year when he agreed, shook hands and signed a deal to stay with us for five years.

"So regardless of what he says now, it's all pissing in the wind really."

Brought to you by AAP © 2024 AAP