A tubby man performed an indecent act in front of a dog walker.
Police are appealing for witnesses after the incident in the woodland at the back of Torfield School, Hastings, on August 4 at 12.40pm.
The woman was walking her dog when she passed a man on the footpath. Moments later he was lying on the ground by a bush with his t-shirt off and committing an indecent act.
He did not say anything and the woman kept on walking.
He is described as white, in his forties, about 5ft 8 tall, of medium/tubby build with dark coloured curly messy hair and a full beard of the same colour.
He was wearing a white t-shirt which had black writing on it that was tied into the style of a crop top. He was also wearing blue jeans.
PC Lee Williams said: "The lady was understandably alarmed by the actions of this man. We would advise anyone who sees someone committing an indecent act or indecently exposing themselves to call 999 immediately.
"This footpath runs alongside a children's play park so there is a risk he could have been seen by young children. We are keen to identify the man and stop him from committing further indecent acts. If you have information email email@example.com or call the non emergency number 101 quoting serial 1049 of 4/08."