$1.4 million worth of painkillers found hidden in car at US-Mexico border Agents found 47,340 40 mg tablets of what appears to have been the oxycodone.

 -- U.S. Border Patrol agents are used to finding drugs stuffed into tight spaces inside vehicles, but a bust on Wednesday was far beyond the normal.

Federal prosecutors in San Diego say agents found 47,340 40 mg tablets of what appears to have been the painkiller oxycodone inside a hidden compartment of a 1999 Honda Accord after it passed through the Otay Mesa Port of Entry. At a street value of about $30 to $40 per tablet, the haul was worth around $1.42 million.

"This is one of the biggest seizures of oxycodone at a San Diego port of entry," Acting US Attorney Alana Robinson said in a statement.

In fact, officials say they believe it is the largest seizure of oxycodone tablets in at least the past five years along the Southwest border.

In a criminal complaint obtained by ABC News, prosecutors say the driver of that Honda, 22-year-old Adriana Morfin-Paniagua, told agents she had owned the vehicle for only a month and was on her way to the Department of Motor Vehicles to get it registered. Agents smelled silicone and began searching. They found a gap filled with silicone and packages inside the compartment.

Morfin-Paniagua was arrested. According to court documents, she is a U.S. citizen and had a valid U.S. passport card.

The complaint says she admitted to agents that she knowingly smuggled the drugs and knew about the hidden compartment. Morfin-Paniagua claimed she was going to be paid up to $1,500 by someone once she returned to Tijuana.

In a field test, the tablets showed a positive test for oxycodone. They are now being forensically tested at a DEA lab to confirm the initial findings. Federal prosecutors say that process should take about a week.

Morfin-Paniagua is charged with importation of a controlled substance. If she is found guilty she could get up to 20 years in federal prison.