Ten years after Sydney woman Katrina Ploy disappeared and washed up dead at a Sydney beach, police have made one more appeal for information.  The 25-year-old disappeared on December 17, 2006, after leaving her parents' Seven Hills home following a Hawkesbury race meeting that she attended with her mother and sister, Tanja.  Her clothes, handbag and car were found at notorious suicide spot The Gap at Watsons Bay early on December 18 but her body was not recovered until Christmas Day at a nearby Sydney Harbour beach.  A post-mortem revealed Ms Ploy's injuries did not result from a fall and her death was treated as a suspected murder.  Police revealed on Monday Ms Ploy may have visited a tattoo parlour on the Great Western Highway in Wentworthville in the early evening before she went missing.  Homicide Squad head Detective Superintendent Mick Willing said Ms Ploy had visited the area no less than four times in the months before her death, twice in a taxi and at least once in her own car.  "She had some reason to be over there ... The mystery remains as to why she was in the area and who she may have been visiting," he told reporters in Sydney.  Police are now offering a $100,000 reward in the hope new information may come to light.  "Somebody out there knows something and we're hoping that this reward causes that person or people to come forward," Supt Willing said.  A coronial inquest in 2010 could not determine how she died and handed the investigation back to police.  Ms Ploy's sister Tanja said it still feels as though the tragic events only just happened.  "It's been 10 years and it's almost like it was yesterday," she told reporters.  "The ongoing effect of what happened as far as my family's concerned is just devastating."  She said her sister gave her family no reason to suspect anything was wrong, as she was looking forward to Christmas and behaving normally for the most part the day she disappeared.  "There was nothing strange about her. The only one thing that was odd was she didn't come (to the races) dressed up, which is very abnormal for her. She was a bit of a princess and that was something odd."  Ms Ploy's former boyfriend Grant Millgate is understood to have told police that shortly after her disappearance he was told that she had wanted to die but couldn't kill herself so had approached a hitman to arrange her own death.  Police would not confirm whether that story has been corroborated but Tanja said this was completely out of character.  "This just came as an absolute shock, I've just got no answers to any of these questions. She's a completely different person than what all these circumstances make her out to be," Tanja said.  Tanja also said her sister and her boyfriend seemed "very happy" before her death.
Police are appealing to the public for help in solving the ten-year-old cold case of a murdered Sydney woman.