A man in New Zealand filmed his sister and another man after the pair took synthetic drugs, commonly known as "bath salts".

The video, posted on Facebook by a man who calls himself Tuakeu Te Maori-Boy, filmed his sister sitting at a table, grunting, swaying and drooling to make people aware of the dangers of drugs. It was viewed more than one million times in a day.

"I know a lot of people won't agree that I put it up cause it is my sister but I don't care, I'm fucking sick of seeing our youth do this shit and tired of our youth doing nothing better," he wrote.

He added an update, saying: "It's basically bath salts which is synthetic stimulants but it could be spice which is synthetic marijuana. Either way both do the same thing."

According to local reports, the man showed his sister the video after she had sobered up – at which point she pledged to seek help.

The most common ingredients found in "bath salts" are methylenedioxypyrovalerone (MDPV) or mephedrone, which affect the central nervous system.

A woman called Deidre Teava, who said she was the aunt of the two siblings, praised the uploading of the video for raising awareness of the dangers of synthetic drugs.

"I won't be sharing the video because watching it once for me was one of the hardest things I've ever had to watch and no doubt majority of you have seen it now," she wrote.

"My nephew Tuakeu Te Maori-Boy done one of the bravest things, sharing a video of his sister and the effects these drugs that are so easily available to anyone on our streets have on people, to create awareness to anyone else who is going through this, to any youth that think they want to go down that road."