The Department of Homeland Security says a man arrested at Honolulu International Airport last week is part of an international drug trafficking organization that manufactured counterfeit prescription drugs, sold the fake pills from an online store on the darknet for bitcoin then converted the digital money into real cash.

A Homeland Security Investigations special agent made those allegations in a search warrant application for the information contained on the cellphone, laptop computer, hard drive and other portable digital storage devices connected to Drew Wilson Crandall, one of the suspects.

Authorities seized the devices from Crandall and his girlfriend when they re-entered the country in Honolulu on May 5. They planned to get married in Hawaii.

Federal prosecutors in Utah charged Crandall with conspiracy to manufacture and distribute the synthetic opioid fentanyl in January. Crandall and his girlfriend were traveling overseas at the time, and prosecutors asked the court to seal the criminal complaint until his arrest.

Following his arrest, Crandall agreed to and is awaiting transfer to Utah. He remains at the Federal Detention Center.

Crandall’s alleged co-conspirator, Aaron Michael Shamo, was arrested at his home in Utah last November on suspicion of possessing fentanyl with the intent to distribute it. Investigators said they seized about 70,000 counterfeit oxycodone pills, 25,000 counterfeit alprazolam pills, also known by brand name Xanax, and $1,227,773 in cash from Shamo’s home.

The investigators said they also seized pill press machines and chemicals used to make the counterfeit drugs from the home and an additional $19,520 from Shamo.

HSI, the IRS, the Food and Drug Administration, the U.S. Postal Inspection Service and the Drug Enforcement Administration say they have been investigating Crandall and Shamo for importing fentanyl from China, using it to manufacture counterfeit oxycodone and alprazolam, then using the mail to deliver the pills to customers in the U.S.

Investigators say Crandall and Shamo paid others, with whom they communicated by encrypted email, to receive the fentanyl from China. They allegedly used the fentanyl to manufacture the counterfeit oxycodone and alprazolam then had the same people who received the shipments send the fake pills to customers who made purchases from their darknet store using bitcoin.

Darknet is a part of the internet that is accessible only through specialized anonymity-providing tools.

Investigators say Crandall’s girlfriend used bitcoin to purchase PayPal My Cash Cards to convert virtual money into real cash.

They said Crandall left the enterprise about the time he and his girlfriend left the country in November 2015 but rejoined a year later to provide customer service and support.

Crandall has yet to respond in court to the charge against him. The lawyer who represents him in Hawaii declined comment.

Shamo pleaded not guilty in December to the charge of possession with intent to distribute fentanyl. He remains in custody with no opportunity for release on bail.