Police have received a number of calls from women out in Halifax town centre last night, being touched in an inappropriate way.
Detectives are investigating the reports and currently have a man in custody that is helping them with their inquiries.
DS Terry O’Keeffe from Calderdale CID said: “We believe this has been going on for some time and there is possibly some other victims that may want to come forward.”
He said the man always appeared to be wearing the same clothes and it is believed he could have carried out similar incidents in other parts of Calderdale.
Contact police on 101.