The American PhD student was fatally attacked at a bus stop in the Auckland suburb of Meadowbank in April this year.
"I remain deeply grateful for the continued, tireless efforts of the police in their pursuit of justice for Kyle.
"Their unwavering dedication to identifying and apprehending all those involved in his murder is commendable.
"While my foremost priority is securing justice for Kyle and ensuring his legacy endures, I am equally concerned for the safety and well-being of all New Zealanders.
"I implore anyone who may have information, no matter how small or seemingly insignificant, to come forward and assist the police.
"Your courage could make all the difference. Together, we can honour Kyle's memory and help protect your communities."
"I want to reiterate to those people with information that the opportunity to tell police what you know is now - please come forward."
Forensic inquiries were ongoing into a machete that was located at Maybury reserve, about 5km from the scene where Whorrall was killed.
"These forensic inquiries are being carried out by PHF Science, and we expect this to take some time to be completed.
"We will be led by the science on where this takes us in our investigation."
Two people are before the courts - a 16-year-old boy charged with Whorrall's murder and a 33-year-old woman facing two charges of being an accessory after the fact.
The trial for the teenager has been set to begin on August 31 next year.
• If you have information, please contact police online now or call 105 using the reference number 250419/9858, or Operation Aberfeldy.
