A section of river in a forest park in Dunmurry has turned bright green due to a tracer dye, it has been revealed.
Colin Glen Forest Park received a number of reports over the past 24 hours of a bright green substance in its river.
On the park's Facebook page, the management committee stressed the substance was a dye and was not toxic. It was a liquid used by the Rivers Agency for testing.
"It's not slime, toxic, waste, Fairy Liquid, a bad case of the flu, aliens, St Patrick's day trial, jelly or any other wonderful suggestion we've seen," the committee said.
"Thank you for all your concern and please do let us know if you see things in the park we should know about."
Green party representative Malachai O'Hara has urged the Rivers Agency to keep the public in the loop after the apparent pollution incident at Colin Glen turned out to be a tracer dye.
"I am very relieved to find that this substance is not pollution but is a tracer dye.
"However, I would point out that this caused quite a degree of alarm among users of the forest park, some of whom have come across genuine pollution incidents in the area in the recent past."
The west Belfast party representative said: "It is in the interests of a healthy environment for park users to continue to report suspicious substances when they come across them.
"I would urge Rivers Agency to let the public know ahead of time if they are carrying out this kind of exercise, rather than stir up this kind of confustion."
Rivers Agency has been asked for comment.