Thames Valley Police is appealing for witnesses after a man was seen inappropriately touching himself in a public place in Milton Keynes on Saturday.
The incident happened at around 11.30am on the redway between Monkston Park and Woughton-On-The-Green.
A woman was running past the location when a man stood in her way and inappropriately touched himself.
The offender is white, aged in his early twenties, with dark brown medium length hair. He wore a navy blue hooded top with a white t-shirt, grey jogging bottoms and black trainers.
Anyone with information is urged to contact investigating officer PC Peter Cave at Thames Valley Police via 101.