Police are appealing for any women who may have been the victim of a flasher to come forward.
The man indecently exposes himself by running in the Lickey Hills Country Park without any jogging shorts.
West Mercia Police have received six separate reports since November 2003 but officers believe there may be more victims.
A man has been arrested and released on bail in connection with these incidents.
Pc Laura Williams, from Redditch police, said: "The man has been seen mostly on Sunday mornings and has exposed himself to lone females or two females walking together in the park.
"Due to the number of reports received, we believe there may be other victims or witnesses who have not as yet contacted the police and so we would appeal to them to get in touch."
Anyone with any information is asked to contact police.