A vandal with a vendetta against cyclists has been pouring oil over a popular bike path, an act that could be deadly.
Police fear Melbourne bike routes are becoming targeted more frequently, with the latest attack following a vandal who scattered a popular bike route with tacks last year.
Cyclist Brittany Slater is the latest rider to fall victim to the oil attack on the Capital City Trail.
She told Nine News she had to visit Royal Melbourne Hospital on Sunday night when her bike slipped out from underneath her, causing her to chip her two front teeth.
"I rode through the oil, the bike slipped underneath me ... I fell forwards on my nose and teeth," she said.
It was not the first time oil had been thrown on the track and riders spotted it three weeks ago.
"When it first happened, I was like, 'that's horrible. Why would someone do that?," Ms Slater said.
"To do it a second time, that's just crazy."
Australian Cycle Alliance President Edward Hore said the vandal had no care for cyclists.
"It's another bizarre situation where a cyclist has been attacked on separated infrastructure away from cars," he told Nine News.
"It's like it's a targeted attack. We're demanding police involvement. There's plenty of CCTV in the area. We need this done because the path is used by up to 900 riders an hour (at peak hours)."
Victoria Police Senior Constable Rueben Larson told Nine News the vandal could face serious charges, including endangering the person.
"As for cameras, we'll be speaking to the local council. One of the issues we've had is a lot of reports have been anecdotal, that's why we're seeking actual witnesses or victims of people who have been involved," he said.
Infuriated cyclists tried to stop another bizarre attack on them last year, that had been ongoing for two years, news.com.au reported.
An unknown culprit had relentlessly been dropping "tens of thousands" of little tacks on a stretch of road that is a hotspot for cyclists.
Riders had been severely injured, one suffered from a brain haemorrhage and broken ribs, and cyclists said it would be only a matter of time until a cyclist hit a tack and slid under a car.
The tacks were tiny but they were a weapon. They were only as big as your fingernail, but sharp as claws.
It's a crime that may seem trivial but the ruthless attacks showed somebody out there had a true vendetta against cyclists who rode along the Yarra Boulevard in the Victorian suburb of Kew.
Cyclist George Mihailides was fighting to put a stop to the dangerous act.
"Everybody thought at the start it was a bit of a joke because you get disgruntled people but usually something like this happens once or twice and they go away," he said in 2016.
"This has just been relentless."
VicRoads hired somebody to sweep the boulevard and only hours later the tacks were sprayed across the tar again.
"There are all sorts of indications that the person is paying close attention to what is going on," Mr Mihailides said.
"We had two protest rides and there were tacks thrown on the road prior to both rides. We are fairly sure the person doing this has a visual of the boulevard or lives very locally."