Chung is scheduled to be arraigned in Belknap Superior Court in New Hampshire next Wednesday, Mortensen adds.
The 32-year-old was found to be in possession of cocaine on June 25 in Meredith, N.H., but he was not arrested at the time, local police chief Kevin Morrow told Mortensen.
"We are aware of the reports regarding Patrick Chung. We will not be commenting while his judicial proceedings take place," the Patriots said in a statement.
A potential NFL suspension won't be handed out until the safety's legal situation is resolved, according to Ben Volin of the Boston Globe, who adds that Chung may avoid any punishment this season since the trial isn't expected to begin until spring 2020.
Chung has spent nine of his 10 NFL seasons with New England, during which he's won three Super Bowls.
The veteran defensive back signed a one-year contract extension in April, keeping him with the club through 2021.