WARREN — Seven people have been charged in an interstate drug smuggling effort that pumped drugs into the Maine State Prison.

The alleged ringleader of the effort was an inmate serving a sentence for a drug-related robbery in Union. The drugs were allegedly being provided by a 71-year-old man in Connecticut who was purchasing Suboxone strips for $5 each, which were being resold for $400 each within the prison, according to the Maine Drug Enforcement Agency.

More arrests are expected.

Arrested was Douglas Mazzotta, 71, of Middletown, Connecticut, who was charged with trafficking in Suboxone and illegal importation of the drug, according to a news release issued Wednesday night by MDEA Commander Scott Pelletier.

The ringleader inside the prison, according to the MDEA, was Paul Milardo, 41, of Cushing. Milardo is serving time for a drug-related robbery. He was charged with two counts of Class A trafficking in Suboxone.

The investigation began in September and, according to police, involved Milardo sending instructions to other prisoners and several people who live in the midcoast area to have Mazzotta ship the Suboxone to the midcoast residents, who then allegedly sent the strips inside greeting cards to prisoners.

During the investigation, agents and U.S. Postal Service inspectors intercepted two shipments of Suboxone strips that were mailed to addresses in the midcoast from Connecticut. A total of 80 Suboxone strips were seized.

Mazzotta mailed Suboxone strips to Maine at the direction of Milardo, according to investigators. Milardo allegedly arranged with prisoners Edward Robinson, Travis Work and Matthew Binnette to have the Suboxone strips smuggled into the prison, according to the MDEA.

Investigators believe Milardo had several people inside the prison dealing the drugs. Prisoners would direct people from outside the prison to transfer money orders to personal accounts or prisoner accounts within the prison for payments to Milardo. Prison commissary items were also used to trade for Suboxone, according to investigators.

In addition to Mazzotta and Milardo, the following individuals were charged:

Christy Nason, 38, of Warren, charged with trafficking in drugs; Edward Robinson, 33, of Randolph, for trafficking in drugs; Lisa Works, 27, of Topsham, for conspiracy to sell drugs; Travis Work, 30, of Topsham, trafficking in drugs; and prisoner Binnette, 30, of Biddeford, trafficking in drugs.

Mazzotta was arrested by the an FBI task force on Jan. 13 in Middletown. He is being held at the Hartford House of Corrections in Hartford. He has waived extradition and will be brought to Maine this week.

Milardo remains at the Maine State Prison in Warren. Nason and Robinson are being held at the Knox County Jail. Lisa Work was issued a summons and is free. Travis Work is in the custody of the Federal Bureau of Prisons on an unrelated charge. Milardo and Binnette remain at the Maine State Prison.

Assisting MDEA and prison investigators were U.S. postal inspectors, the Knox County, Lincoln County and Sagadahoc sheriffs offices, and Maine State Police.

Additional arrests are expected as the investigation continues.