TAMPA, Fla. (WFLA) — Two Florida men are behind bars after they were caught pumping thousands of dollars worth of “liquid gold” from a local restaurant early Thursday morning, according to authorities.

The Flagler County Sheriff’s Office said Rui Gen Lin, 48, of St. Johns, and Rong Chen, 41, of Gainesville, were caught in the act of pumping used cooking oil, nicknamed “liquid gold,” from a restaurant in Palm Coast.

A deputy sheriff performing a business check at Woody’s Bar-B-Que around 3:15 a.m. spotted the duo pumping thousands of gallons of used cooking oil from behind the restaurant into a white box truck.

When deputies took a look inside the truck, they found bolt cutters, a pry bar, a pump, and several “large storage containers” containing more than 7,000 pounds of used cooking oil valued at around $5,000.

Deputies said Lin owned and operated a Jacksonville-based recycling company, L & L Recycling, LLC, but did not have permission to take the cooking oil.

“They own a company that buys and recycles old cooking oil but, in this case, they tried to increase their profits by stealing the oil,” Flagler County Sheriff Rick Staly said. “Used cooking oil is often recycled to make diesel fuel and used in other products.”

According to the Wall Street Journal, the value of cooking oil has risen 80% in the last year to 66 cents per pound. The sharp increase in value has incentivized thieves to steal the commodity — referred to as “liquid gold” in articles from WSJ and S&P Global — and flip it for thousands of dollars.

“With the price of oil rising, the theft of used cooking oil is increasing across the country. This was a great job by Deputy Kyle Gaddie for seeing something suspicious while on patrol and stopping to check it out,” said Sheriff Staly.

Sheriff Staly also referred to the two suspects as “grease-bags” and welcomed them to the “Green Roof Inn” — his nickname for the local prison.

Local restaurants missing used cooking oil are urged to call authorities at 386-313-4911 to file a report as detectives continue the investigation.

Lin and Chen were charged with “burglary of an unoccupied structure and possession of burglary tools with intent along with misdemeanor petit theft,” according to a press release. Both have been booked into the Sheriff Perry Hall Inmate Detention Facility, where each is being held on a $5,500 bond.