YORK – At least $1 million in cash was discovered inside a tractor-trailer Friday afternoon during a routine inspection along the turnpike.

Maine State Police said they found the stash of cash after detaining the driver and a passenger while they examined driver logs.

The driver, 35-year-old Jhon Rivera-Ramirez, was ultimately arrested for falsifying logs. He was later released on bail.

State police said Ramirez was traveling with a passenger, Jose Javier Perez, 46, who was not charged in the stop.

Police did not say where the men were coming from or where they were going. State Police Lt. Thomas Kelly said there was no other cargo inside the trailer.

“They were hauling cash,” Kelly said. “That’s all they were hauling.”

Investigators from the State Police Commercial Vehicle Enforcement Unit made the initial stop. Police said the rig is registered in Texas.

When officers inspected the back of the rig, they found an odd sight – five gallon pails lined with pink bags and stuffed with bills of varying denominations.

Kelly said $1 million is only an estimate and probably a conservative one.

“It hasn’t been counted yet,” he said. “We’re still early into the investigation.”

It was, he said, the largest cash seizure in Maine’s history.

By Friday night, Ramirez remained free on bail. Federal agents were expected to join the probe.

In recent years, the smuggling of bulk currency has become the preferred method for criminals to move illicit proceeds across our borders, according to Maine Public Safety Spokesman Stephen McCausland.

It is a crime to smuggle or attempt to smuggle over $10,000 in currency or monetary instruments into or out of the United States.