The six-candidate race for the Democratic nomination for Brooklyn district attorney has at times resembled an action-packed drama fit for the wide screen. Now, it could be headed to a theater near you.

A filmmaker who has won an Emmy award and made this year’s documentary “Enron: The Smartest Guys in the Room,” Alex Gibney, is at work on a project examining allegations that the incumbent district attorney, Charles Hynes, improperly used his authority to silence a critic of the Brooklyn Democratic machine, John O’Hara.

In a telephone interview yesterday with The New York Sun, Mr. Gibney, 51, declined to set a timetable for the release of the documentary, which is tentatively titled “Mr. Smith Goes to Brooklyn.” He said it was “unlikely, but not impossible,” that the film would be out before September 13, the day that Brooklyn Democrats head to the polls to decide whether Mr. Hynes will receive the party’s nomination for a fifth term.

“I usually don’t make films to make or break a candidate,” Mr. Gibney said. But he added: “If it seemed important to rush it forward, I would do it.”

Mr. Gibney noted that he produced the 2002 documentary “The Trials of Henry Kissinger,” an expose focusing on the former secretary of state, in only three months.

Just as Mr. Gibney’s 2002 documentary emerged from a pair of articles in Harper’s Magazine by Christopher Hitchens, the filmmaker said his interest in the O’Hara project was piqued by an article Harper’s published late last year.

That piece, by Christopher Ketcham, chronicled O’Hara’s bitter legal battle with prosecutors from Mr. Hynes’s office. O’Hara, who failed in each of his six bids for City Council and state Assembly in the 1990s, was arrested in 1996 for allegedly registering to vote from an apartment that did not qualify as a “fixed, permanent and principal home” under state election law.

In 1999, at his third trial, O’Hara was sentenced to five years’ probation, fined $20,000, and ordered to perform 1,500 hours of community service.

O’Hara is the first person in the history of the state to be convicted for failing to establish a legal residence inside a voting district.

“I’m not a lawyer, but it does seem unusual that he paid such a high price for such an insignificant crime,” Mr. Gibney said.

Mr. Ketcham’s article charges that Mr. Hynes chose to prosecute O’Hara as a “favor” to a political ally, Assemblyman James Brennan, whom O’Hara challenged in a 1996 primary.

“That article was a work of fiction,” a Hynes spokesman, Jerry Schmetterer, said yesterday. “How can you base a documentary on a work of fiction?”

Mr. Schmetterer said the district attorney came “very close” to filing a libel suit against Harper’s and instead fired off a 1,300-word rebuttal, which the magazine printed in full.

Meanwhile, Mr. Gibney’s camera crew is following O’Hara, a former attorney who was disbarred after his conviction, as he fulfills his community-service requirement by picking up trash for eight hours a week at Shore Road Park.

The crew is also trailing a civil rights lawyer, Sandra Roper, who garnered an unexpectedly high 37% of the vote when – in her first bid for elected office – she challenged Mr. Hynes in the 2001 Democratic primary. After the race, Ms. Roper was indicted on charges of forging documents and stealing $9,000 from a client. The charges were dropped in February.

Ms. Roper, now a candidate for civil court judge, said judicial ethics rules leave her “constrained in what I can say about Mr. Hynes.” But she said she was indicted “selectively and discriminatorily” in retaliation for crossing the district attorney in 2001.

Mr. Gibney said he has not yet contacted the district attorney’s office to arrange an interview with Mr. Hynes, but the filmmaker said, “My approach is always to try to talk to everyone.” Mr. Schmetterer said the district attorney would gladly cooperate with Mr. Gibney and his crew.

Mr. Hynes’s Democratic challengers are the former head of Attorney General Eliot Spitzer’s government corruption bureau, Mark Peters; a state senator, John Sampson; a former homicide prosecutor, Koch aide, and deputy commissioner of trials for the New York Police Department, Arnold Kriss; an election attorney, Paul Wooten; and a former prosecutor, Braxton Freddy Fenner.