A 59-year-old woman was walking in the area when a man grabbed her from behind and assaulted her.
The incident happened around 4.25pm on Tuesday June 19 on the public footpath leading from car park 1, to car park 2 in Longniddry Bents.
The victim screamed and the suspect made off towards car park 2.
Police are carrying out an ongoing inquiry to identify the male responsible and have urged anyone who may have information to come forward.
He is described as white, in his fifties, around 5ft 9ins tall with a large overweight build and wearing a white polo-shirt with coloured hoops and grey jogging bottoms.
Constable Kris Macleod from Haddington Police Station said: “While the victim has not been injured, this attack has left her extremely distressed and we are eager to hear from anyone who can help us trace the suspect.
“If you were in the area of the car parks at Longniddry Bents on Tuesday afternoon and witnessed what happened, then please contact police immediately.
“We would also urge anyone with any other information relevant to this ongoing investigation to get in touch.”
Those with information can contact Haddington Police Station via 101 and quote incident number 2518 of the 19th June. Alternatively, an anonymous report can be made to the charity Crimestoppers on 0800 555 111.