A man says he was held down and repeatedly punched by a nude man angry that the alleged victim's dog was not on a leash at Sauvie Island's clothing-optional beach.

The assault allegation is under investigation by Oregon State Police, who on Sunday asked for the public's help identifying the suspect.

The alleged incident took place between noon and 3 p.m. on Thursday. The assault caused "visible injury," police said. Police said the suspect is a regular at Collins Beach and has "reportedly accosted" others about their off-leash dogs.

The police description includes the suspect's height, weight, build and notes his receding hairline but naturally leaves out clothing since he wasn't wearing any.

State police Fish and Wildlife troopers are continuing to investigate the assault and anybody with information on this suspect, including past encounters is asked to call the OSP Northern Command Center at *OSP or email Trooper Joe Dezso at Joseph.Dezso@state.or.us.

-- The Oregonian