James Gandolfini drunkenly vowed "every other day" to quit 'The Sopranos'

His co-star Steven Van Zandt, 73, who played Tony's 'consiglieri' Silvio Dante on the HBO hit, has now opened up about how James struggled making the series.

He says on new documentary 'Wise Guy: David Chase and The Sopranos': "Every other day, we would go to a bar. We would have the exact same conversation.

"We would get drunk. He'd say, 'I'm done. I'm not going back'.

"I would say, 'Okay. You've got a hundred people depending on you here'. "He's like, 'Yeah, yeah, okay'. He would come back. But a few times, he would disappear for a few days. You know, it just got to him."

'Wise Guy' also includes interviews with 'Sopranos' creator David, who recently said James left him mesmerised with his "otherworldly" eyes.

He told a CBS News retrospective on the creation of the landmark show in honour of its 25thanniversary this year: "He's incredible. Well, the whole thing's about his face and about his eyes, actually. "There's something about his eyes that - it was otherworldly."

David also said the humour in the show was so prevalent he could "never" figure out whether it was a comedy.

He added: "I guess it's like life. I don't know."

David previously told People he was glad the show's fanbase was still going strong, saying it left him with a "tremendous sense of gratitude".

He added: "I can't remember this happening with any other television show ever."

David also said about James' performance: "Look at the show, and there you see it. It's a cliché to call that stuff magic, but he was totally inhabiting that fictional creature.

"It's the best thing I've ever done. It's probably the best thing I ever will do."