A technical analysis released yesterday by the Harvard University Art Museums pours cold water on a filmmaker’s claim to have discovered a trove of paintings by Jackson Pollock. Experts found within the paintings both pigments and media that they say were not available until decades after Pollock’s death.

In 2003, Alex Matter, the son of the photographer Herbert Matter and the painter Mercedes Matter, found 32 small paintings wrapped in brown paper in a storage locker in Wainscott that had belonged to his parents. Notes on the wrapping, as well as the drip style of the paintings, led Mr. Matter to assert that the paintings were executed between 1946 and 1949 by Pollock, who was a longtime friend of Mr. Matter’s parents.

Mr. Matter’s claim set off a fierce debate in the art world. An art historian at Case Western University and former member of the Pollock-Krasner authentication board, Ellen Landau, said the paintings were authentic Pollocks. But the artist’s estate, represented by the Pollock-Krasner Foundation, dissented. (Lee Krasner was a painter and Pollock’s wife.) Guild Hall in East Hampton had planned to show the Matter paintings last August, as part of local tributes to Pollock on the 50th anniversary of his death, but as the controversy heated up, Guild Hall pulled out. Mr. Matter offered the paintings to several other museums for exhibit, but only one signed on: An exhibition of the paintings will open at the Everson Museum of Art in Syracuse on June 16.

The Harvard study, written in dispassionate scientific terms, will likely be a source of keen disappointment to Mr. Matter. (Mr. Matter, Ms. Landau, and representatives of the Harvard art museums all declined interviews yesterday.) Harvard’s experts took three of the paintings and tested the pigments, the media (the material in which the pigment is dissolved), and the cardboard supports. They found several pigments and media that were not available until after —in some cases, long after — the period when Mr. Matter claims the paintings were executed.

A brown paint found on one of the paintings was only developed in the early 1980s. Pollock died in 1956. Other paints were not available until the early 1950s, after the date Mr. Matter attributes to the paintings he found, or the early 1970s. Two of the paintings contain media that the report’s authors believe were not available before the early 1960s, and the third uses a binding medium that probably wasn’t sold before the 1970s.

An associate professor of art history at New York University, and co-curator of the 1998 Pollock retrospective at the Museum of Modern Art, Pepe Karmel, said the report casts serious doubt on the attribution of the works to Pollock. “This technical analysis is deeply troubling,” he said. “It suggests that at least some of the materials used in the pictures were not available until decades after the pictures are said to have been made.”

The testing was extensive, and some of the results were inconclusive in regards to attribution. Samples of the cardboard support, for instance, were tested for elevated levels of carbon-14, resulting from atmospheric bomb testing, which began in 1955. They didn’t contain those elevated levels, suggesting that the cardboard predated the bomb testing. But that could simply mean that a pack rat artist did the paintings on old cardboard.

The director of the Everson Museum, Sandra Trop, said the report made no difference to the museum’s interest in showing the works. “We think that the more controversy there is, the more interest there will be and the more people coming to see the show,” Ms. Trop said. She said she is considering having a chemist come to speak about the analysis Harvard conducted.

“We were the only museum who signed on to do this, because we could see the education potential,” she said. “People are going to look at these paintings a lot more carefully than they’ve ever looked at paintings in their life.”

Mr. Matter is not the only person in recent years to claim to have discovered new paintings by Pollock. A documentary released this fall by Picturehouse, “Who the #$&% is Jackson Pollock?,” followed the journey of a retired truck driver named Teri Horton who has spent over a decade trying to get a painting she bought for $5 at a thrift shop authenticated as a Pollock.

Ms. Horton’s case rests largely on the argument of a forensic specialist who claims to have matched a fingerprint on the back of her painting to one on a paint can in Pollock’s former studio in East Hampton, as well as (since the film’s completion) to one on an authenticated 1943 Pollock that hangs at the Tate Modern.

The director of the film, Harry Moses, said that Ms. Horton’s tenacity is one reason that people in the art world are beginning to put faith in forensic analyses, like the tests conducted by Harvard. “She’s been battling the art world to a standstill for 15 years, and because of her, people are beginning to take the forensic stuff a lot more seriously than they ever have before,” Mr. Moses said. “It’s very much to her credit that it’s beginning to happen.”