Police officers are appealing for witnesses after a man indecently exposed himself on the footpath that runs adjacent to the railway tracks, near to Pytchley Road, Kettering.
The incident happened between 10am and midday yesterday (Tuesday) when a woman was walking along the footpath and heard a wolf whistle.
She looked around and a man emerged from the bushes at the side of the path, pulled down his shorts and exposed himself to her.
The offender is described as a white man in his mid-thirties with short brown hair, a beard and of broad build.
He wore a blue t-shirt, dark-coloured dirty work shorts and work-style boots.
He had a mole on his face above his beard.
Witnesses or anyone with information about the incident can call police on 101 or Crimestoppers anonymously on 0800 555111.