Officials in Langford, B.C. have a mystery on their hands after the Goldstream River suddenly turned neon green on Wednesday afternoon.

The suspected fluorescent dye ran through the river for about an hour as horrified Goldstream Provincial Park visitors watched in awe.

Goldstream Provincial Park -- located west of Victoria – is known for its pristine natural environment and wildlife, including annual salmon runs.

Suntanu Delal, spokesperson for the Ministry of Environment, told that the incident could have been caused by a water tracing dye used in testing of sanitary water systems.

Water samples were taken Wednesday for testing to evaluate the substance and determine whether it poses any environmental risk.

Fire Chief Bob Beckett thinks the green waters may have been the result of an ill-conceived prank.

"In all likelihood it's a hoax. It may be a non-toxic substance but it's unfortunate that we had to utilize all sorts of resources to investigate this," he said.

Beckett said that a Langford water fountain also mysteriously turned green yesterday.

It could be a hoax that's gaining popularity in B.C. In August, a prankster attending the Shambhala Music Festival in the Kootenays dyed the Salmo River a similar neon green hue. The chemical turned out to be non-toxic.

Keilih Gates, a naturalist who works at Goldstream Provincial Park, said that the incident was very startling to staff and park visitors.

"It was actually quite a dramatic effect. It looked bright neon green -- the same colour as anti-freeze -- and it went through the river quite quickly," she said. "It's concerning because it shows how quickly it can reach wildlife."

Samples from both the river and water fountain are currently being analyzed and lab results have not yet been released.