HOULTON – Maine Drug Enforcement agents arrested seven southern Aroostook County men this week after an extensive investigation.

Darrell Crandall, MDEA division commander, said Friday afternoon that the men were arrested by agents assigned to the Aroostook Regional Task Force over the past two weeks.

According to Crandall, David Landry, 56, of Houlton was arrested and charged with aggravated trafficking in methadone. The offense is considered aggravated because Landry was convicted on a felony drug-trafficking charge six years ago.

Landry is believed to have been supplying large quantities of methadone to 48-year-old Donald Flanders of Houlton, who also has been charged with trafficking in methadone.

The MDEA believes Flanders sold a majority of the methadone tablets to Nathan Richards, 25, of Patten, who Crandall said allegedly was selling them at the retail level. A charge of trafficking in methadone has been lodged against Richards.

Aaron Richards, 28, of Patten, who is Nathan Richards’ brother, also was arrested and charged with trafficking in oxycodone.

Also arrested in connection with the investigation were 33-year-old Charles Hawkes on a charge of trafficking in methadone, John Neureuther, 31, on a charge of trafficking in heroin, and Casey Corbett, 19, on a charge of trafficking in oxycodone. All three men live in Houlton.

Crandall said Friday that agents believe the criminal activity was going on for “some time” and added that agents have been seeing increasing sale and abuse of methadone over the past year.