Alleged sightings of any sort of otherworldly being tend to be easily dismissed by a lack of a) concrete proof and b) official interest. It's safe to say that, whatever level of conspiracy theory you subscribe to, the local government's going to want to know about any fantastical creatures turning up in their jurisdiction.
A fact that make Kiryat Yam, an otherwise unassuming sea town on Israel's Mediterranean cost, quite fascinating. As local officials are allegedly offering a $1million dollar reward for anyone who can provide verifiable video proof of the mermaid that's said to inhabit its waters. So frequent are sightings.
Occasionally mistaken for one of the town's many sunbathers, the last 15 years have seen near hundreds of reported incidents - some from local residents well aware of legends, and some from visiting tourists totally oblivious to the whole thing. It's not quite solid evidence, but the video above stands as the clearest example documented thus far.