SEATTLE — The two contract delivery drivers working for Amazon had a clear-cut assignment: They were supposed to bring packages from a warehouse south of Seattle to a post office for shipping, or sometimes drive to Seattle-Tacoma International Airport to pick up items that were being returned to the company.

Instead, the FBI said in a search warrant affidavit unsealed last month, they routinely stole the items and sold them at pawn shops.

A police detective last summer noticed that one of the drivers had dozens of pawn shop transactions, and thus began an investigation that uncovered a theft ring that sold millions of dollars’ worth of stolen goods on Amazon.com in the past six years, the FBI said.

According to the search warrant affidavit, two storefront businesses posing as pawn shops bought the goods from shoplifters, then had the items shipped to Amazon warehouses, where they were stored until sold online.

Entities associated with the alleged ringleader did at least $10 million in sales on Amazon since 2013, FBI agent Ariana Kroshinsky wrote in her affidavit. The agency said it was awaiting further records from Amazon to determine the full amount.

No charges have been filed as of last week, , though investigators have raided the pawn shops and the home of the man identified as the ringleader, Aleksandr Pavlovskiy, 44, of Auburn. Pavlovskiy’s lawyer, Cristine Beckwith, did not return a message seeking comment.

A man who answered the door at one of the shops last week identified himself as Alex and told The Associated Press his business was legitimate, that he kept good records and he should not be in any trouble.

Among those who provided stolen items to the pawn shops were the two contract Amazon drivers, Kroshinsky said.

In a statement, Amazon said it does not tolerate fraud.

“When we learned there was an investigation into two contracted drivers, we cooperated with law enforcement by providing them the information they requested. Additionally, we strictly prohibit inauthentic or stolen goods from being offered in our store and take action when sellers do not comply,” the statement said.

The investigation began last summer when a police detective in Auburn, a south Seattle suburb, was perusing a record of pawn shop sales and noticed that one man had made 57 transactions. It turned out to be one of the drivers.

He had received nearly $30,000 selling items to the pawn shops between February and July last year, the affidavit said. Police initially arrested the driver, but released him from jail to avoid disrupting their larger investigation.

The other driver, identified as Abbas Zghair, was believed to be a roommate of the first. Amazon told investigators that Zghair stole about $100,000 worth of property, including gaming systems, sporting goods and computer products — items he sold to one of the pawn shops for less than $20,000, the agent wrote.

In an unrelated case, Zghair has been charged with murder after police said he shot and killed a man in an Auburn field in March, then fled to the Canadian border, where he was arrested trying to cross with a fake ID. He’s being held on $2.5 million bail.

Both drivers worked for Amazon contractor JW Logistics, based in Frisco, Texas. It was unclear how long Zghair had worked for the company, but in 2015, he was convicted of reckless driving in Lewis County after leading police on a chase in excess of 100 mph, running red lights, driving across multiple lanes of travel and crashing into a field.

Detectives staked out the pawn shops, Innovation Best in Kent and Thrift-Electro in Renton, and observed that they appeared to be paying shoplifters cash for new items from Home Depot, Lowes and Fred Meyer department stores. Unlike typical pawn shops, they didn’t make sales; instead, the products were moved to a warehouse and to Amazon “fulfillment centers,” from where they were shipped when they were sold on Amazon’s website by sellers using the handles “Bestforyouall” or “Freeshipforyou,” the affidavit said.

According to a database of pawnshop transactions reviewed by Auburn police, the suspect pawn shops paid more than $4.1 million to sellers who brought them nearly 48,000 items in the past six years. The items included allergy medication, razors, electric toothbrushes and tools in their original packaging. Detectives also conducted undercover operations in which they sold new items in their original packaging to the shops, which accepted them no questions asked, Kroshinsky wrote.

Amazon has several requirements for third-party sellers on its website: They must provide a business name, address, contact information, a valid credit card, and tax identity information.

Jon Reily, a vice president for the digital consultancy firm Publicis Sapient and previously the head of e-commerce user experience for Amazon Devices, said preventing the sale of stolen goods is a major challenge for the company, but retailers can be held liable if they don’t do enough to ensure they’re not selling stolen goods. Because it’s impossible for Amazon to review “every Tide pod” that’s sold on its site, the company will likely need to do more to vet sellers, Riley said.