In a press release, investigators said the first incident occurred on July 2 at approximately 10:25 a.m.  at Alias ​​​​Grace Park, near Yonge Street and Gamble Road, in Richmond Hill.
At the time, police say a mother and her two young children were in the park when a male suspect approached them.
The suspect then pulled down his pants and exposed himself to the family, police said.
Police said a day later, they received three additional reports of a suspect with the same description being exposed to people in the area of ​​Valmont Avenue and Waterstone Street.
Images of the suspect were released by investigators Monday in an effort to identify him.
He is described by police as a man in his 20s or 30s of East Asian descent.  He is five feet seven inches tall, weighs 170 pounds and has short black hair.
He was last seen wearing a white T-shirt, shorts, a black backpack and white shoes, police said.
Anyone with information regarding any of the reported incidents is asked to call York Regional Police at 1-866-876-5423, ext.7241 or Crime Stoppers.