The neighbor was Jackson Pollock, the avatar of Abstract Expressionist painting who was sometimes described by art critics as a painter of the unconscious, or the subterranean. Pollock and his wife, the artist Lee Krasner, lived in the tiny Long Island village of Springs, near Mr. Potter's home in Amagansett, until Pollock died in a car crash in 1956.

Mr. Potter, who was 94 when he died of pneumonia on Dec. 15 in a Southampton hospital, told friends he had spent years trying to write a novel based on the life of his brilliant and mysteriously inconsolable friend, but never felt able to capture the multitudes Pollock contained.

So the book he published instead in 1985, "To a Violent Grave: An Oral Biography of Jackson Pollock," was a collection of many narratives about Pollock: selections from hundreds of taped interviews Mr. Potter conducted with family members, friends, former friends and fellow artists, all of them trying in some way to describe the charismatic formlessness that defined him.

Mr. Potter's was one of several biographies of Pollock published in the 1980s that served to revive interest in Pollock's work — and helped set off a scramble in Hollywood to make a movie about this colorful and sometimes violent master of modern art.

In the decades before his Pollock biography, Mr. Potter made a success of his construction business in a booming East End economy of summer-home building. He also published two children's books and two nonfiction works: "Disaster by Oil" (1973), about the environmental danger of oil spills, and "Men, Money and Magic" (1976), a biography of Dorothy Schiff, the society doyenne and longtime publisher of The New York Post.

But "To a Violent Grave," which was his last book, entangled him in an emotional and legal contest that lasted a decade.

Soon after its release, a production company representing Barbra Streisand and Robert De Niro bought the film rights. When the authors of another biography, "Jackson Pollock: An American Saga," which won a Pulitzer Prize, signed a competing deal in 1990 with another film company, Mr. Potter accused them of having plagiarized his work. The authors, Steven Naifeh and Gregory White Smith, sued Mr. Potter over the accusation.

The dispute dragged on for years. The movie that was finally released in 2000, "Pollock," starring and directed by Ed Harris, was made by the company aligned with the Naifeh-Smith book.

Even so, during filming of the movie, Mr. Potter met frequently with Mr. Harris to share his memories of Pollock as well as some of the notes he took for his novel, said Helen Harrison, director of the Pollock-Krasner House and Study Center in Springs, in the home the artists shared, where some scenes were shot. "Even though he lost in the contention, Jeffrey wanted to help with the film in any way he could," she said in an interview.

In interviews at the time of the movie's release, Mr. Harris said his enduring interest in portraying Pollock was first inspired by reading Mr. Potter's book.

Jeffrey Brackett Potter was born into an affluent and patrician New York family in Manhattan on April 12, 1918, to Mary Barton Atterbury and Joseph Wiltsie Fuller Potter. His father, a classmate of Franklin Delano Roosevelt at the Groton School, was a Wall Street stockbroker. Jeffrey broke with family traditions by dropping out of Groton and working as a newspaper reporter, factory machinist and seaman. Rejected by the Army during World War II because of poor eyesight, he served with the American Field Service, attached to the Royal Indian Army, as an ambulance driver and medic in the Burmese campaign against Japan.

In addition to his wife, Priscilla Bowden, his survivors include four children from two previous marriages, Job Potter, Manon Potter, Gayle Basso and Horatio Potter, and five grandchildren.

The Jackson Pollock whom Mr. Potter met in 1949 had already received rave notices in the art world and was beginning to draw attention from magazines like Time and Life. But he was short of money. One day, hearing that Mr. Potter planned to demolish an old barn, he offered himself for hire. "He said that heavy work was for him, that he knew his way around demolition," Mr. Potter wrote in his book. Mr. Potter said he planned to do the work himself.

The reply from Pollock, a former farm boy, offered a glimpse of the boyish machismo inside the tragic hero of Action Art, as Abstract Expressionism was sometimes called.

"O.K., O.K.," Pollock said, walking away, "but after you've hurt yourself — wrenched your back, stepped on a rusty nail — don't forget you know somebody who knows what he's doing and can take it."

Mr. Potter later lent Pollock a lawn mower that he used to earn money by cutting his neighbors' grass.