However, although Jenkins' body was discovered by a motorist, their vehicle wasn't the one believed involved in the incident.
It was also unclear if the driver of the vehicle involved even knew that they had hit someone.
Police were also unsure how long Jenkins had been on the road for.
Patterson said today they were still keen to hear from anyone who had travelled along Owairaka Valley Rd not only around 2.30am, but also in the several hours leading up to the discovery of his body.
Police wanted to hear from anyone who travelled along Owairaka Valley Rd between 10pm on Wednesday, August 11 and 2.30am on Thursday, August 12, Patterson said.
This included anyone with dashcam footage and anyone with CCTV cameras along Arapuni, Owairaka Valley and Mellsop roads.
"We have the utmost sympathy for Joseph's parents and his family and friends, who are understandably traumatised by his death.
"Our inquiry team is working hard to support them as much as we can, and to provide them with answers about Joseph's death."
Anyone with information could call the police's non-emergency 105 number or email Detective Sergeant Anthony Hodgson at anthony.hodgson@police.govt.nz.
Those getting in touch should quote the file number 210812/6788.