Updated

Dozens of FBI agents, Pennsylvania state officials and members of a treasure-hunting group dug in a remote Pennsylvania site earlier this week, on rumors of Civil War-era gold being buried there.

A 155-year-old legend has it that a Civil War-era gold shipment bound for a U.S. Mint in Philadelphia was either lost or hidden northeast of Pittsburgh around the time of the Battle of Gettysburg in 1863.

President Abraham Lincoln reportedly ordered the shipment to help pay Union Army soldiers, Dennis Parada, owner of local treasure-hunting group Finders Keepers, told WJAC-TV.

"I’m not going to quit until it’s dug up," Parada told the Philadelphia Inquirer, "and if I die, my kid’s going to be around and make sure it’s going to be dug up.

“There’s something in there and I’m not giving up.”

"I’m not going to quit until it’s dug up, and if I die, my kid’s going to be around and make sure it’s going to be dug up. There’s something in there and I’m not giving up."

— Dennis Parada, owner of Finders Keepers, a treasure-hunting group

Based on different stories, the shipment was composed of either 26 or 52 gold bars, each weighing 50 pounds, meaning it would be worth $27 million to $55 million today.

Local lore that the federal gold might be buried at the Dents Run site in Benezette Township, Pa., about 135 miles northeast of Pittsburgh, caught the FBI's attention.

President Abraham Lincoln reportedly ordered a gold shipment to be made to Philadelphia, for payment to Union Army soldiers. (AP)

So earlier this week agents from the bureau and officials from the Pennsylvannia Department of Conservation and Natural Resources (DCNR) set up a search area off Route 555, the Courier-Express reported.

The site is west of Driftwood, where a crew delivering the gold was attacked in an ambush, lone survivor Sgt. Jim Connors reportedly told his Army superiors at the time, the Philadelphia Inquirer reported. But the Army reportedly doubted his story and Connors died in a “western outpost,” leaving the loot unfound.

This week the FBI wouldn't say why it was at the site, revealing only that it was conducting “court-authorized law enforcement activity.”

Historians have cast doubt that the shipment of gold was lost on its way to Philadelphia. Finders Keepers also said Pennsylvania’s Historical and Museum Commission claims the legend of the lost gold is a myth, the Inquirer reported.

But the lost treasure recovery group has insisted for years that it discovered buried gold in a state forest at Dents Run (within the township) using a high-powered metal detector, but federal law wouldn't allow it to conduct a dig in search of more, the Courier-Express reported.

A spokesman from the Pennsylvania DCNR said that the group previously asked to excavate the site, but elected not to pay a required $15,000 bond.

The spokesman also referred questions on Tuesday's activity to the FBI, and Parada said he was under FBI orders not to discuss the site.

The Associated Press contributed to this report.