SUN CITY, Ariz. - A rare and "lost" Jackson Pollock painting worth millions was found in a Sun City garage in January last year.

Since then, J. Levine Auction & Appraisal, a Scottsdale-based auction house, has spent more than a year and tens of thousands of dollars authenticating the painting, according to a press release.

The painting is expected to sell for at least $10 to $15 million, according to a pre-sale estimate by the auction house.

The "lost" painting was originally owned by Jenifer Gordon, of New York. She was a known life-long friend of Peggy Guggenheim's sister, Hazel Guggenheim McKinley, and Clement Greenberg, an influential visual art critic.

Gordon bequeathed the painting to her half-brother, who lives in Sun City.

“Interestingly, this estate first came to our attention when we were contacted to take a look at a signed 1992 L.A. Lakers poster,” said Josh Levine, owner and CEO of J. Levine Auction & Appraisal. “We ended up signing a contract to auction the contents of the estate, and that’s when we found many of the paintings stored away.”

The painting was found among a collection of pieces from other distinguished artists, such as Kenneth Noland, Hazel Guggenheim McKinley, Jules Olitski and Cora Kelley Ward.

An untitled gouache painting sent Levine on an 18-month-long journey to authenticate it as an unsigned Pollock. He hired a private investigative team and a forensic expert to investigate.

According to the forensic report, the painting is from the mid-twentieth century. No pigments or binding media introduced in the late 1950s and '60s have been detected.

“Based on their work and findings, I believe this painting was one of Pollock’s missing gouaches in his catalogue raisonné or from the period of 1945 to 1949,” Levine said.

The painting is going up for auction Tuesday, June 20 at J. Levine Auction & Appraisal, located at 10345 N. Scottsdale Road in Scottsdale.

"The forensic report really just reaffirmed what I already believed to be true based on the provenance," Levine said. "I've spent hundreds of hours researching how this Pollock could end up here in Arizona, and I am confident that this is an original Pollock."

A free, public preview will take place on Monday, June 19 from 4 p.m. to 7 p.m.