PORTLAND (AP) – The origin of a banner supposedly used at a reunion of the 20th Maine Infantry unit that fought at the Battle of Gettysburg is being questioned, a report published Tuesday said.

Gettysburg National Military Park is trying to find out whether the flag it recently purchased for $10,500 is authentic, the Portland Press Herald said.

Friends of the National Parks at Gettysburg believed the banner was 115 years old when the group gave the National Park Service money to buy it from a prominent Massachusetts antiques broker.

The banner was believed to have been used during an anniversary gathering for the unit, which fought during one of the Civil War’s most important battles.

But now, an artist named Jim Compratt of Canon City, Colo., told the newspaper he created the banner in 2002. Compratt said he sold it to a Kennebunk merchant for $165.

Compratt said he recognized the banner this weekend when he saw a photo of it on the Web site of the Press Herald and Maine Sunday Telegram.

Cindy Hamilton, who owns the Americana Workshop in Kennebunk, told the Press Herald that she bought the banner from Compratt, and then sold it to a private dealer for $300 as a new item.

The banner’s ownership has changed several times before its purchase earlier this month by Friends of the National Parks at Gettysburg. With each sale, its value increased, Hamilton said.

On Monday, Gettysburg National Military Park officials began investigating the banner’s authenticity after being contacted by the Maine newspaper.

“We are taking it seriously,” said park spokeswoman Katie Lawhon. “But we are not rushing to judgment.”

The banner is said to have flown at Gettysburg in 1889 at the reunion of the 20th Maine. The 42-inch-tall, canvas banner features a scene of Little Round Top at Gettysburg.

Lawhon said Greg Goodell, supervisor of museum services at the park, had established the banner’s authenticity.

But Compratt said his wife sewed the banner on a modern sewing machine and he used modern latex paint for the letters and background.

Compratt said the banner is not a reproduction, just a product of his own imagination. “I just made it up,” he said.

AP-ES-11-23-04 0847EST