Footage showing brazen thieves on a busy Auckland street snipping through bicycle locks in a matter of seconds has been released by police.

The four short CCTV clips were filmed on Broadway in Newmarket over the past few weeks.

In each case, it takes the thieves - including two young boys with their father - less than 10 seconds to snip through bicycle locks with chain cutters.

Acting Inspector Graeme Anderson said many bikes that were stolen were worth thousands of dollars.

"But when it comes to the lock, we often find owners are using a $20 lock that is easy to snip."

The footage demonstrated that even in busy locations, opportunistic thieves were not always deterred.

He encouraged cyclists to buy solid D-locks that could not be easily removed.