The incident happened around 3pm today where a man is alleged to have indecently exposed himself by the adventure playground, on Marsden Road.
Officers are currently searching the area for the man who is white, between 5ft 10ins and 6ft tall, slim and aged in his early 50s. He had rimless glasses and was wearing blue jeans and a black fleece. He spoke with what has been described as a northern accent.
Police commander for Portsmouth, Superintendent Will Schofield said: ‘I understand that a number of residents have been made aware of this incident via social media and that pictures of a possible suspect have been shared.
‘I appreciate the community’s concerns about this incident but would urge people not to take the law in to their own hands which could put at risk any future prosecution.
‘If you believe you know who this male is please contact the police as soon as possible.’
Police are urging anyone who can identify the man or who witnessed the incident to contact them on 101 quoting incident 597 of today’s date.