"A number of vehicles that have been seized are under guard. We will work through the complex scene ... over about three kilometres at this stage."
"If you have information about any member of the public or anyone close to you that you have heard that may be involved in this incident, and indeed those that are responsible, I urge you to come forward."
Scene examinations were carried out on Grange Road and Telegraph Road, Parnell said.
Riddell's personal Facebook account shows a cobra snake.
Friend Jacob Skilling posted a tribute to his "brother", who gave him "more than friendship, brotherhood and mentorship".
"You are a rock to so many, you are a power like no other you have so much influence and strength.
"I really can't believe your gone my brother. Your vessel may be gone but your spirit soars in high in the sky residing with god [sic]," he wrote.
Bruce Duce also posted a tribute.
"I only knew you for a few years but definitely one of the most solidest boys i've ever meet you kept it 113 per cent all the time [sic]."
A tangi was held for Riddell yesterday.