A Bar Harbor couple is suing a Portland police officer, saying he arrested them without provocation after they recorded a separate police interaction on their cellphones.

The Portland Police Department has opened an internal investigation into the incident but would not comment on the status of that inquiry because it is a personnel matter that is not yet concluded, the Portland Press Herald reports.

The lawsuit, brought with the assistance of the American Civil Liberties Union of Maine, says that Jill Walker and Sabatino Scattoloni were charged with obstructing government administration on May 25 in downtown Portland.

The lawsuit says the couple was filming an interaction between five officers and a woman. They were about 25 feet away and were not interfering with the officers, Walker said in an interview Tuesday.

Sgt. Benjamin Noyes, a 17-year veteran of the force, told the couple to move off the sidewalk, and when they asked why, they were arrested, the lawsuit said.