James Gandolfini was just about to start a documentary about America's learning disabled prison population at the time of his death.

The actor, who suffered a heart attack and died in Italy on Wednesday (19Jun13), was hoping to start work on his third film project with director Jon Alpert upon his return to New York.

Alpert, who shot two films about wounded U.S. war veterans with The Sopranos star, tells Msnbc, "He knew that people with learning disabilities, if they got an opportunity, if they got a chance at a good education then finally they could accomplish anything and this was a documentary we were making.

"We found out that 60 per cent of the prison population in the United States has a learning disability... and that's what he wanted the country to understand."

Alpert has also opened up about the man who became a great friend, revealing Gandolfini had a huge heart and never tired of his fans, despite a reputation that suggested he was painfully shy.

The director adds, "I never kissed a man before I kissed Jim Gandolfini... He really cared for people, he wanted to do something to help people. He said, 'I'm a celebrity, I want to use this in a way that's gonna help,' and he worked really hard at it. He did a good job.

"And he was always so gracious when people came up to him; he couldn't go anywhere in New York City without anybody stopping, wanting to get their picture taken with him, talk to him and he had time for everybody.

"I never saw a man like that. I've seen lots of actors, lots of celebrities and at some point you've had enough and Jim was always ready to share and to talk with anyone.

"You were always part of his team... He wanted to share every part of his goodness... He always made us all feel welcome."