Senior Sergeant Peter van de Wettering of the Waikato Police District Command Centre said police initially thought Jones had collided with a median barrier.
However, a truck driver had since told police he looked in his rear view mirror and saw a motorcyclist tumbling down the road.
"The truck driver stopped further up the road and called police and thought he might have been involved in a crash because he saw in his wing mirror a motorcyclist tumbling down the road.
"It appears that the deceased has collided with his motorcycle with the back end of the truck and trailer unit.
"The truck driver would not have felt a thing. If it weren't for him looking in his wing mirror we might never have known that.
"It was fortunate for us and his (Jones') family that he saw that and rang it in. It has not been left as a mystery as to how this man has fallen off his bike."
Mr van de Wettering said police were appealing to members of the public who might have seen the incident.
"The case will be referred to the coroner but it is still under investigation by our traffic unit at Huntly who will be working with the coroner to establish the cause of death and why and how this happened."
Jones' charges relate to alleged offending in the 1970s and 1980s in the Eastern Bay of Plenty. The complainants were aged between 5 and 16 at the time.
Jones' lawyer, Tiffany Cooper, said she heard about Jones' death a couple of hours after the crash.
"He died tragically this morning. We were just notified," she told the Rotorua Daily Post.
Jones, who was Mr New Zealand between 1997 and 1999, owned Sunny Gymz in Whakatane before moving to Auckland.
The Court of Appeal's decision overturning the original convictions was issued on December 9 last year was originally suppressed but Justice Mark Woolford today lifted suppression, given Jones' death.
Justice Woolford also dismissed the charges against Jones and disposed of the retrial.
The Court of Appeal decision said the judge in the first trial had incorrectly instructed the jury relating to propensity and the summing up "undermined or misstated the defence of collusion".