The tip was given to police after a $100,000 reward was posted in a bid to solve the cold case.
Kirsty, 15, was last seen alive on the afternoon of December 31, 1998, when she left her Ashburton home to walk her Labrador-cross, Abby.
Abby was found the next day tied to a tree near the Ashburton River along with a pair of Kirsty’s underwear and boxer shorts.
Her body was found 17 days later in the Rakaia Gorge by two men who told police their reason for being at the location was that they were looking for a cannabis plot.
The Star can reveal the person nominated was associated with two men who were investigated for potential involvement in Kirsty’s murder but later ruled out.
The nominated person had not featured in the police investigation until the reward was posted in July.
The two men initially suspected were not Kirsty’s father Sid or brother John, who police focused on for a number of years.
Detective Inspector Greg Murton, who is investigating the cold case, yesterday said he would not comment about The Star’s information. It would be unhelpful to the investigation, he said.
