A man allegedly committed a lewd act in Batley.
The offence happened on Common Road, Staincliffe, at around 9.50pm on Friday.
A 22-year-old woman looked out of a window where she saw a man allegedly committing the act of outraging public decency.
He was disturbed and left on foot in an unknown direction.
The man is described as white, in his late teens to early 20s and possibly had blond hair.
He was wearing a grey hooded top which was worn with the hood up.
PC Teresa McCarter, of the Batley and Spen Neighbourhood Policing Team, said: “We are keen to speak to anyone else who believes they have seen this man in the Staincliffe area around the time of this reported offence.”
Anyone with information should call Batley and Spen NPT on 101.