An "elderly" man who made lewd gestures towards a woman at a park with her daughter was later captured in a photograph, police say.

The woman was at the park on Fulham and Westham ways in Epping North with her young daughter at 11.40am on Sunday.

While she was watching her child, she heard "kissing" noises being made by a man who was standing about 10 metres away. The man had a young child with him on a three-wheel push along tricycle.

A short time later she looked at the man to find him staring at her and making lewd gestures.

The mother rang a friend who came to the park and took a photograph of the man.

Epping Sexual Offence and Child Abuse Investigation Team detectives described the man as being elderly, aged in his 60s, of thin build, 165-170cms tall and with an Italian accent.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au