The incident occurred at around 8.10am on Monday, November 15, when a woman walking her dogs on a cycle path near to Greenbank Road noticed man acting suspiciously close to Fullarton Arches and the Scott Road bridge.
The man then walked into a wooden area, and went on to carry out an indecent act in front of the woman.
She then confronted the man, who fled into the direction of the Scott Road bridge.
Police describe the man as being white and in his twenties. They believe he may have spoken with an Eastern European accent.
The suspect was also seen to put on a surgical-type face mask as he approached the main road.
Inspector Andy Dolan from Irvine Police Station said: “The woman has been able to provide mobile phone footage of the man and we are conducting enquiries in the local area to establish his identity.“I’d appeal to anyone who was in the area on Monday morning and who may have seen a man acting suspiciously to come forward and report this to police.“Equally anyone who can help us identify and trace the man responsible should get in contact with officers as soon as possible.”Anyone with information should contact Police Scotland by calling 101 and quoting incident number 1178 of November 15 2021. Alternatively, an anonymous account can be given to Crimestoppers on 0800 555 111.