Details around what had happened at the BMX track were sketchy, he said, but it appeared Mr Clubley hit his head against an object while riding.
The Whangarei BMX Club was aware of the accident but members did not know how it had happened.
Club president John Romer said it had taken place just hours after club members, who had a fun day on Sunday afternoon, left the tracks.
Mr Clubley was not a club member, he said.
"It's horrific to see anyone hurt himself ... It's quite a dangerous sport and unfortunately when we're not there it's an open track, just like the skate park in terms of safety," Mr Romer told the Advocate.
Mr Clubley's family has asked for privacy.