The couple faced backlash on the internet after they posted a video on Instagram of the moment a waterfall turned electric-blue to indicate that they were having a male baby, as guests cheered. They later deleted the video which also showed swans made of white balloons. A giant question mark symbol made of pink and blue balloons was also kept by the bank.
But copies of the video were shared thousands of times on several platforms. The unidentified couple is now being investigated by the Brazilian environment ministry which says they polluted the Queima Pé river, which is a popular tourist destination in the state of Mato Grosso and a primary water source for the nearby central-west town of Tangará da Serra.
The Queima-Pé waterfall, 6km from Tangará da Serra, is located at a height of 18 metres, and is used for waterfall baths, rappel and other tourist activities, reported Brazilian news website Midiajur.
It said periods of drought have caused a frequent supply crisis in the municipality.
Thousands of people commented on the video, slamming the couple for allegedly putting polluting substances in the water. One user said: “What happened to cutting into a cake. Why does nature keep getting damaged because these people think they’re special?”
Another critic wrote: “Because who needs drinking water when you have ‘likes’?”
In a statement released by the secretary of state for the Environment of Mato Grosso (SEMA), the department said it will investigate the couple to determine what products were used to dye the waterfall and if there is any environmental damage.
Gender reveal parties have often in the past been criticised for extreme stunts. In May last year, an explosive device set off at a gender-reveal party ignited a wildfire and resulted in the expectant parents being charged a $500 fine.