A naked man confronted two young girls and indecently assaulted one of them as they walked a short distance ahead of their families at a Coromandel beach yesterday.
Police are searching for the man, who ran away when members of the public and family stepped in.
The 5-year-old and 7-year-old cousins were walking along the Riverview Rd Reserve at the northern end of Cooks Beach when they were approached by the naked man about 7.30pm.
The younger girl was indecently assaulted before the man fled in a silver hatchback car.
The two girls had been a short distance ahead of their family members as they walked back from the beach.
"It was then the girls were confronted by this naked man who indecently assaulted the five-year-old girl," Detective Inspector Chris Page said.
Police were now interviewing the family and girls to gather more information about the assault.
The offender has been described as a clean-shaven caucasian with dark hair. He was carrying a red and yellow towel.
Police would like to hear from anyone in the area at the time who saw a man fitting his description.