The van, described as a "white Honda Odyssey-type", was found as a burnt out wreck.
Police are treating the death as a suspicious; family and friends of Turei seek retribution.
Social media posts refer to "muttz" and "dog s***", a clear reference to the rival Mongrel Mob gang whom they believe to be responsible.
"Let those who ride decide."
Armed police were called into the eastern Bay of Plenty to keep a lid on simmering tensions, as dozens of gang members travelled to Ruatoki to pay their respects at Turei's tangi today.
Among those are Manga Kahu, a chapter of Black Power, another traditional rival to the Mongrel Mob.
The Tribesmen and the Mongrel Mob have a long history of violence and retaliation, particularly in the stronghold of nearby Murupara.
A large group of Mobsters had gathered at the Pararaki Marae for the unveiling of a plaque, when Turei and his brother rode past on their motorcycles on Saturday afternoon.
The pair had just left the wedding ceremony at the Anglican church at Raukokere and were on their way to the reception celebrations.
His brother did not see Turei get knocked off his bike, but was pursued by a convoy of vehicles.
The Herald understands the death of the 38-year-old Turei is the latest in a recent string of escalating incidents between the Mob and the Tribesmen.
The head of the homicide inquiry, Detective Inspector Lew Warner, declined to answer questions because the investigation is ongoing.
Instead, a spokeswoman for the police referred to a statement issued earlier in the week.
"Police have now located a burnt-out, white Honda vehicle near the banks of the Raukokore River, a short distance from where Don Henry Turei Junior died.
"Police would like to speak to anyone who has knowledge about this vehicle, how it came to be burnt out, or saw the vehicle driving in the area around 2-3pm on Saturday.
"We are also interested in talking to anyone who was driving on State Highway 35 near Ruakokore between 12pm and 4pm on Saturday 26 November 2016."
"Police would also like to hear from anyone who may have witnessed the crash, or anyone who believes they may have information that would help with our investigation."
Please contact Bay of Plenty Police on 07 349 9554 if you can help.
Information can also be provided anonymously via Crimestoppers on 0800 555 111.