Geraldton Police would like to speak with anyone who may have witnessed a theft that occurred yesterday.

Police say that around 5pm on Sunday 14 December 2014, an elderly female was walking along Marine Terrace in the Geraldton CBD when her purse was stolen.

A passer-by who witnesses the event gave chase and the offender dropped the purse.

The offender is male, early to mid 20's, approx 5"10 and with dark ski. He was wearing a black t shirt and black track pants, with a red baseball cap.

Police are requesting anyone with information regarding the incident to contact Crime Stoppers on 1300 888 000.