Doubts about the authenticity of 32 newly discovered works by American painter Jackson Pollock are now swirling after a scientific analysis suggested they may be fakes.

The Pollock-Krasner Foundation, set up under the will of Pollock's widow Lee Krasner, said it has selected six of the paintings for further examination by Richard Taylor of the University of Oregon's Department of Physics.

Taylor and his team analyzed Pollock's previous work, dated from 1943 to 1950, and compared them to the 32 new pieces, unearthed last May by filmmaker Alex Matter, a childhood friend of Pollock's. Matter said he discovered the paintings among the possessions of his late parents, stored for three decades in a warehouse on Long Island.

Taylor uses a method called fractal analysis — a technique that searches for geometric patterns that recur in paintings. Taylor says despite the chaos in Pollock's drip paintings, the artist's works had specific patterns.

"Pollock's specific fractal signature has not been found in the submitted paintings," said Taylor in his report, published in the journal Nature.

"The analysis has also revealed that the patterns vary between paintings, indicating that they may have been painted by different hands."

Charles Bergman, head of the foundation, said he would not declare the new works fakes until further investigation. Six of the paintings were selected because they had "significant differences" from Pollock's authenticated works.

Art historian Francis O'Connor, who heads the foundation's investigation, said he had reservations about the paintings because they reveal "no relation to Pollock's known stylistic development."

But Ellen Landau, a Pollock art expert, authenticated the new pieces and says she does not trust fractal analysis because it's a "very new and contested field in art authentication."

Landau concedes the 32 works do not look like "standard Pollock" and instead praised them for their "experimental quality." She promised to release her own study of the paintings on Feb. 23 in Boston.

The new works include 22 drip paintings and two enamels on paper; the rest are unfinished works on board.

Pollock stopped using brushes in 1946 and began dripping and pouring paint over canvas.

He died in a car crash in 1956.