Fencing will cordon off Whangarei's Pohe Island BMX track to the public from October, following the death of a local police officer earlier this year.

A coroner's report released today, confirms Detective Sergeant Andrew John Clubley, who fell off his bike and onto his head - died of brain trauma.

Whangarei BMX Club president John Roma says the club and the council have been left with no other option but to fence off the track.

"There has been additional signs put up at the bottom of the ramp, middle of the ramp and the top of the ramp. Unfortunately we're still on occasion seeing people there doing what they shouldn't be doing."

But Mr Roma says there will be open days held for the public, who can enjoy the track under supervision.