"We've been working with the tractor driver to pinpoint the timings of his sightings and everything suggests that this is our vehicle of interest, a Jeep Cherokee. A minute or so later George was shot,'' he said.
Police want to hear from anyone who travelled along Ongaroto Rd on March 19, particularly between the hours of 2.30pm and 3.15pm who may have seen the vehicle or anyone acting suspiciously.
Mr Taiaroa returned from his lunch break about 25 minutes before he was killed, said Mr Anderson.
A motive for the shooting. has not yet been established.
"It's been two weeks now since George was killed and we have found nothing to suggest that George was anything but a friendly, hard-working, family man.''
Anyone with information is asked to contact the investigation team on 0800 Kingswood (0800 546 479) or anonymously via Crimestoppers on 0800 555111.