"It's a very ingenious way of doing things and I've never seen anything like this," said Hermitage Deputy Police Chief Edward Holiga.
Holiga said his department is investigating whether the truck is linked to at least three thefts since 2005. In the latest, about $4,500 worth of diesel fuel was reported stolen April 28 from the underground tanks of the Tic Toc Food Mart in Hermitage.
Police issued a surveillance photo of the pickup and trailer believed to be involved in the thefts and received a tip that led them to a property in North Bloomfield, Ohio, about 30 miles northwest of Hermitage.
Police spotted the truck and trailer on the property Tuesday and obtained a search warrant that was executed Wednesday.
The trailer contained a straw wall that concealed a wooden partition. The partition hid a siphoning mechanism and an empty 15-foot long propane tank.
Police believe someone inside the trailer would siphon diesel fuel from underground tanks at fuel stations by lowering a hose through the trap door and using the pickup's engine to power a vacuum that drew the fuel into the tank, Holiga said.
Police also found several storage tanks on the Ohio property, including a 5,000-gallon tank containing about 500 gallons of diesel fuel.
Holiga said police in Ohio are investigating at least one theft there, too.
Because police are continuing to investigate the thefts, Holiga said he doesn't expect his detectives to file charges until next week.