Federal investigators say authorities made the biggest fentanyl pill bust in Minnesota history when they broke up a trafficking operation that used the mail to send toy animals stuffed with the drug to the state from Arizona.

Six men and women were charged in U.S. District Court in St. Paul with conspiracy to distribute the powerfully addictive opiate from August to December in 2022.

One of the investigating agencies, the Washington County Sheriff's Office, said the unprecedented haul totaled 280,000 pills that weighed more than 66 pounds and had a street value of roughly $2.2 million.

"We continue to see the devastating impacts of fentanyl in our communities," Sheriff Dan Starry said in a statement Friday.

Starry, whose office pointed out that the U.S. Drug Enforcement Administration considers 2 milligrams of fentanyl a potentially lethal dose, added, "With this seizure, we know that hundreds, if not thousands of lives have been saved."

One of the defendants, 27-year-old Fo'Tre Devine White of St. Paul, also was charged with being a felon in possession of a firearm and possession of a machine gun.

Prosecutors said one of two pistols White had in his possession was modified to fire multiple times with a single squeeze of the trigger.

U.S. Attorney Andrew Luger identified White's co-defendants as Cornell Montez Chandler Jr., 24; Robiel Lee Williams, 23; and Quijuan Hosea Bankhead, 30, all of St. Paul; along with Stardasha Christina Davenport-Mounger, 24; and Shardai Rayshell Allen, 24, both of Minneapolis.

Authorities say several of the defendants traveled to Phoenix to obtain fentanyl pills from suppliers, hid them in stuffed animals and mailed them to addresses in and around the Twin Cities.

Law enforcement in Dakota, Ramsey and Washington counties learned of the trafficking and launched a joint investigation that led to the seizure of six packages.

All six defendants have appeared in court and have a joint hearing scheduled for March 7. White remains jailed without bond. The others were released from custody after posting bond.

The Star Tribune contacted attorneys for each defendant Friday for comment, and four replied. Attorneys for Bankhead and Allen declined to comment.

Chandler's attorney, Frederick Goetz, said his client has pleaded not guilty. "He looks forward to his day in court to refute these allegations," Goetz said.

Williams' attorney, Kenneth Udoibok, said his client "must be given the presumption of innocence."

Agencies involved in the investigation included the U.S. Postal Inspection Service, U.S. Homeland Security Investigations, the Dakota and Washington counties drug task forces and the Ramsey County Violent Crime Enforcement Team.

There were 1,343 drug overdose deaths in Minnesota in 2022, according to preliminary data released in October by the state Department of Health. That is a slight decline from 1,356 the year before. Both totals are about twice what was reported in 2018.

Fentanyl, which is 50 times more potent than heroin, was involved in 92% of all opioid-involved deaths and nearly two-thirds of all overdose deaths statewide, according to the early data for 2022.