The alleged sighting occurred several hundred metres east of the last confirmed sighting of Tracey, who vanished while walking to her Henderson home about 9.30pm on January 29, 1976.
The person took down his details and said they would be in touch, Mr Ross told Fairfax. But that never happened.
He tried to pass on the information several more times, most recently in 2011, when Detective Sergeant Murray Free was in charge of the case. Mr Free said he would come and see him, but he did not, Mr Ross said.
However, police have dismissed Mr Ross' claims.
In a statement provided to the Herald, Detective Inspector John Sutton, of Waitemata police, said Mr Free took a written statement over the phone from Mr Ross in 2011.
Mr Free had overseen the enquiries into Tracey's murder since 2004 and had extensive knowledge of the case. That included taking a large number of witness statements, examining and assessing information provided, and reviewing, contrasting, comparing and collating the last-known confirmed sighting of Tracey.
"Det Sgt Free knows this case in minute detail, including the timings of Tracey's movements and that of witnesses and their locations... Det Sgt Free made an assessment on the information provided by Mr Ross against the large amount of material provided by witnesses and gathered over the years.
"Det Sgt Free's assessment was made based on his vast insight of this case, on information that Mr Ross, nor the public are privy to. Based on the information provided, it was determined that Mr Ross' sighting was highly unlikely to be that of Tracey Patient, however his statement was placed in the file for future reference, where it remains."
Police had also been unable to find any record of Mr Ross having contacted the murder enquiry team in 1976, Mr Sutton said.
"There is a large amount of documented information from the original enquiry which has been indexed in a manual card file and this does not contain any record of information provided by Mr Ross.
"As we have previously indicated, if Mr Ross has new information to provide to the enquiry team, we would welcome the opportunity to speak with him again."
The investigation into Tracey's murder remained active, he said.
Following police publicity in January, police received more than 200 calls and detectives have been following up on the information provided.
"As recently as last week, a member of the investigation travelled to Australia to carry out further enquiries."
Case timeline
Jan 29, 1976: Tracey goes to a friend's house on Chilcott Rd, Henderson. The friend walks her halfway home to the intersection of Great North Rd and Edmonton Rd at about 9.30pm. Tracey is last seen outside 295 Great North Rd, Henderson - only five minutes walk from her home.
Jan 30, 1976: A man walking his dog finds Tracey's body in a bush area on Scenic Drive. She has been strangled with a stocking.
Next few months, 1976: Police launch large-scale investigation into the murder. Police investigate hundreds of suspects and follow numerous lines of inquiry.
Mar, 1976: Anonymous woman calls Youthline saying she saw a blonde girl, thought to be Tracey, on Great North Rd with a man in a brown suit. Both got into a brown car which drove off just after 9.30 pm. Despite public appeals, the woman caller is never found.
Nov, 1978: Anonymous caller tells police a signet ring Tracey owned is in a rubbish bin outside a chemist in Avondale. Officers find the ring, which Tracey was believed to be wearing when she went missing.
Jan 10, 2006: Airing of Sensing Murder episode in which psychics investigate the case.
Feb 1, 2010: Revelation police have interviewed a man in connection with the case.
Jan 29, 2011: Police say continued interest from media organisations has triggered several new tips from the public.
Nov, 2015: A team of eight police investigators relaunch fulltime investigation into the case.
Jan 28, 2016: Police reveal they are following new leads in the case.
Jan 29, 2016: The 40-year anniversary of Tracey's disappearance.
July 2016: Pensioner Gary Ross claims he saw a blonde girl being escorted by a middle-aged to elderly man on who was holding her by the elbow and walking along Great North Rd in Henderson near the Henderson shops and several hundred metres from the last reported siting at about 9.30pm on Jan 29, 1976. He claims he made several attempts to report it to police including the day after Tracey went missing and the last in 2011.
