Federal authorities are expected to spend today combing through the inventory of a Western Pennsylvania gun dealer to determine exactly what was stolen from his truck while it was parked outside a restaurant in King of Prussia.

According to Upper Merion Township police, at least 24 firearms, including machine guns and sniper rifles, valued at more than $200,000, were stolen from a Ford F-350 pickup around 8:30 p.m. Sunday.

The weapons belonged to a dealer, Arms & Ordnance, in Warrendale, a suburb of Pittsburgh, said John Hageman, spokesman for the Philadelphia division of the Bureau of Alcohol, Tobacco, Firearms and Explosives. He said the ATF was working with Upper Merion police on the case.

"It is a federal crime to steal guns from a licensed gun dealer," Hageman said. In this case, the dealer had a Class 3 license, which allowed him to buy and sell the type of weapons stolen, he said.

State records show that Arms & Ordnance is a fictitious name registered to F. Charles Logan. No one answered the phone at his store yesterday.

Hageman said laws covering machine guns varied from state to state and jurisdiction to jurisdiction. For a dealer to obtain a Class 3 license, the municipality in which he or she lives also has to approve, he said.

Because machine guns are illegal in New Jersey, no one can get a Class 3 license to sell them to New Jerseyans, Hageman said.

Upper Merion police said the owner of the weapons had left a gun show at the Valley Forge Convention Center and had stopped at Kildare's Irish Pub on DeKalb Pike to have dinner before returning to Pittsburgh.

In addition to the guns, Hageman said that almost $5,000 in cash was stolen from the truck. He said that once the inventory check was complete, an alert would be issued.

"These guns are now crime guns," he said. "ATF investigators are working with Upper Merion police to get those guns off the street and back into custody. These are very dangerous weapons."

Anyone with information about the theft is being asked to contact Upper Merion police at 610-265-3232.

Contact staff writer Nancy Petersen at 610-696-4932 or npetersen@phillynews.com.