DEXTER — Nine people charged with participating in a central Maine cocaine and oxycodone ring are pleading not guilty.

Police say the defendants were arrested in an early morning drug raid after an investigation by Dexter police that took more than 18 months. They say more arrests are likely. The arrests come after a wiretapping effort in which hundreds of hours were recorded.

The defendants appeared in federal court in Bangor on Tuesday and pleaded not guilty. Police charged 57-year-old Roger Belanger of Corinna; 47-year-old Mark Tasker of Dexter; 26-year-old Greg Tasker, 38-year-old John Williams and 42-year-old Cynthia Williams of Stetson; and 21-year-old Whitney Chadbourne, 23-year-old Corey Pomerleau, 66-year-old Eugene Moulton and 46-year-old Antoinette Perreault of Harmony

Twenty-nine-year-old Kelli Mujo was also arrested in Rhode Island.