Police have sealed off a park near Eltham High Street this morning with forensic officers reported on site after a woman was assaulted last night.
Police vehicles are stationed around Eltham Park South and Glenesk Road.
Officers and sniffer dogs are searching the area.
Police were called at 12:28am after the victim, in her 30s, was hit and knocked unconscious. Her injuries are fortunately not life-threatening.
Anyone with information can call Police on 101 quoting CAD 240/31MAY or Crimestoppers on 0800 555 111.