Strike Force Willunga has been set up to investigate the alleged armed robbery and sexual touching of a teen in Moss Vale.
Around 6pm last week a 14 year old girl was taking her dog for a walk in Lackey Park when she was approached by three males.
The trio threatened her with a knife and demanded money.
The 14 year old was then pushed to the ground and sexually touched after the knife was used to cut the top she was wearing.
Police are urging anyone who was in Lackey Park between 3.30pm and 7pm last Wednesday, to contact Southern Highlands Police or Crime Stoppers.
IMAGE CREDIT: Wingecarribee Council