Det Snr Sgt Croudis said he could not release the contents of the information received until further work had been done.
The last confirmed sighting of Pridding was on the morning of November 8, 1994.
The 34-year-old left his beloved dog and his car with a friend in St Kilda, saying he would return in a couple of hours, and left with an associate in a Nissan Bluebird car.
Much of the episode of Cold Case, which screened on TVNZ, focused on the driver of the car and his possible role in the disappearance.
It was almost a month before Pridding, a mechanic and low-level cannabis dealer, was reported missing.
At the time of Pridding's disappearance, several people had come forward with information.
However, police revealed that from early on, they were aware key people were actively feeding them misinformation.
Det Snr Sgt Croudis said those people ''will know only too well who they are''.
They had initially made statements to the police at the behest of another person.
''They have almost exclusively withdrawn that information now, and said that those sightings, or sets of circumstances didn't occur, and they had been encouraged to say these things to police by an individual.
''The fear of that individual has waned over time.''
Police urged anyone with information about what happened to Pridding to come forward.