Earlier this month, five people were arrested in the city over a large number of alleged bike thefts - but police are still investigating several other incidents, said Senior Sergeant Roy Appley, of Christchurch police.
CDHB chief executive Peter Bramley has also warned staff and visitors about thieves targeting bikes around Christchurch Hospital.
"Since September last year, 14 bike have been reported stolen from a variety of locations around the Christchurch Hospital campus," said Bramley in his latest Canterbury DHB CEO Update.
The spike in bike thefts has prompted Appley to warn people to be vigilant with their bike security in the central city.
He said the thefts are taking place outside commercial and retail outlets, even when the bikes are locked up.
"If bikes are not properly and securely locked to a hitching post, they could be stolen," said Appley.
"People should consider a high-quality D-lock or similar to deter would-be thieves.
"When you first buy your bike, please ensure that you record its serial number and take a photo of the bike.
"Put the details of that number somewhere safe, tell your insurance company, just make sure you note it down," said Appley.
You can also upload the details to www.snap.org.nz to keep a permanent record.
Said Appley: "These thefts are happening during day-light hours; people are having their daily transport stolen."
He also warned people buying bicycles online to be careful they are not buying a stolen bike.
"With the number of thefts growing in the central area, it’s wise for prospective buyers to be careful of what they purchase.
"The majority of these stolen bikes are being sold via online market places."
Appley recommended purchasing bikes from a genuine retailer - and preferably use websites based in New Zealand.
"If you’re purchasing from an individual, we suggest you request proof of ownership, or perhaps some form of ID.
"If the seller is not able to or refuses to provide these, it’s possible the item may be stolen.
"Generally speaking, if the deal is too good to be true, it often is," said Appley.
