It is suggested that he suffered a heart attack while riding uphill, but that has not been confirmed.
Senior Sergeant Paula Enoka, of Queenstown, said the pair performed CPR on the 33-year-old who was riding on the Fernhill Loop riding track.
Two St John paramedics were flown to the scene about 3.45pm after McGarry's companions called another biking companion, who in turn alerted emergency services.
However, the rider was pronounced dead about 4.20pm.
The unexplained death has been referred to the Coroner, and police would take statements from his riding companions and partner today.
"We're still investigating what his movements were over the weekend," Sen Sgt Enoka said.
Meanwhile, tributes flowed in for McGarry from around the world.
Sad to learn about Kelly McGarry. Such a positive guy with a fantastic attitude towards life. Thanks for always pushing the limits.
— Julie Kikla (@jkix) February 1, 2016
Very sad day as Kelly McGarry has passed away. He was an amazing mountain biker and he will be terribly missed.
— Karenn Gonzalez (@KarennMeyer) February 1, 2016
Shred hard, shred often. Rest easy big man #KellyMcGarry
— Joe Mitchell (@joeisspecial) February 1, 2016
A permanent grin, a positive soul, an inspiration to be yourself and embrace life. Kelly McGarry will be missed. pic.twitter.com/2irDEIe4VS
— GiroSportDesign (@GiroSportDesign) February 1, 2016
Ride in peace Kelly McGarry
— Tobiॐ (@tobiask8np) February 1, 2016
Rest in peace Kelly McGarry. You will be sorely missed #KellyMcGarry
— Andrew Cook (@MR_AJDC) February 1, 2016
The news about Kelly McGarry is so sad I actually can't believe he's gone, you won't be forgotten Kelly
— Ellie (@elmarieeeee) February 1, 2016
McGarry was the only New Zealander ranked in the world's top 20 for slopestyle and as co-owner of Elevate Course Building built the slopestyle course for the Crankworx World Tour event at Skyline Rotorua Gravity Park next month.
McGarry's bike sponsor YT posted a statement on their website saying the company was deeply saddened and shocked by the death of "a truly unique character".
"We were informed about his death in the morning and are petrified, shocked and heartbroken about losing one of our family members. Kelly was a warm-hearted, friendly and relaxed guy. He stood for the true essence of mountain biking through every aspect of his life. Our thoughts and prayers go out to his family, girlfriend and his friends.
"The mountain bike world lost an exceptional character," the statement read.
- Guy Williams and NZ Herald.
