Roberts, 22, was taken into custody early July 7 in Montreal after someone called police to report a fight in the couple's room and officers arrived to find Peters with a bloody nose and a bite mark.
Roberts was released hours later because her 26-year-old beau did not want to press charges.
"It was an unfortunate incident and misunderstanding. Ms. Roberts was released after questioning and the couple are working together to move past it," Peters' publicist said on his behalf in a statement issued to UsMagazine.com Tuesday.
The couple have been dating since spring 2012.
She is joining the cast of Peters' show "American Horror Story" this season.