By Jill Serjeant

NEW YORK, May 16 (Reuters) - The latest film about infamous swindler Bernard Madoff, whose decades-long Ponzi scheme cost clients more than $17 billion, ends with a question.

"Do you think I'm a sociopath" Madoff, played by Robert De Niro, asks journalist Diana B. Henriques in a prison interview.

"The Wizard of Lies," premiering on Time Warner Inc's TWX.N HBO on Saturday ahead of an international rollout, leaves the question unanswered. Almost a decade after Madoff was convicted of masterminding the biggest financial fraud in U.S. history, the filmmakers put their focus on the devastating consequences for his family.

"This is a dark tragedy of a man's betrayal of his family," said director Barry Levinson. "This was a man who ultimately destroyed his family, and the financial lives of thousands and thousands of people."

"It's not for us to decide is he or isn't he (a sociopath), because if he were, so what It doesn't help anything," said Levinson.

"Wizard of Lies" follows several documentaries, a stage play and a 2016 TV miniseries about Madoff, reflecting an enduring fascination with the quiet, fatherly figure and his apparent lack of remorse or explanation for his actions.

Madoff, 79, is serving a 150-year prison term after pleading guilty in 2009 to multiple charges of fraud. His son Mark committed suicide two years after his father's arrest and his younger son, Andrew, died of lymphoma in 2014. Ruth, his wife of more than 50 years, has cut off contact with him.

"I don't know if I ever really came to understand him," said De Niro, who is seen as an Emmy front-runner for his enigmatic portrayal of Madoff.

Henriques, the New York Times journalist whose prison interviews and 2011 book formed the basis for the HBO film, said that while Madoff became "a very easy target for anger and outrage" over the wider 2008 Wall Street meltdown, his story has a wider resonance.

"This was betrayal on a Shakespearean scale," said Henriques, who plays herself in the film. "When someone comes forward who has so flagrantly violated the trust of those who loved him, I think we all feel shaken by that."

Henriques conducted two prison interviews with Madoff and exchanged emails and letters, concluding that he is a man "with a pathological inability to see himself as a failure."

She believes he would likely watch the HBO film if he gets the chance.

"Over the years he has clearly demonstrated that he follows the news about himself. I do know that he read the book ... He hated the title but he told me he appreciated that I had been fair to his family. So I would be surprised if he had an opportunity to see this film that he wouldn't take it," she said.

(Reporting by Jill Serjeant; Editing by Tom Brown) ((jill.serjeant1@thomsonreuters.com; 646 223 5968;))

Keywords: TELEVISION WIZARD OF LIES/