A $50,000 reward is being offered to find whoever is responsible for placing tacks on bike paths and roads in Melbourne's inner northeast.
Police say hundreds of bicycle tyres have been punctured and some cyclists have been seriously injured as a result of the tacks at Kew.
They have been deliberately dumped or placed on and around Yarra Boulevard since 2014, and police estimate it has cost bike riders thousands of dollars in repair costs.
"The tacks also pose (a risk) to all road users, including pedestrians and those walking with pets as they can cause significant injury. It simply has to stop," Eastern Region Assistant Commissioner Glenn Weir said in a statement.
Two mobile CCTV units will also be used along Yarra Boulevard in a bid to catch the culprit.
Anyone with information can contact Crime Stoppers on 1800 333 000 or user the Crime Stoppers online reporting page.
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