An anti-cannabis video in Australia comparing users to super-sized sloths could encourage people to use the drug, leading researchers involved in the campaign have claimed. 

The “you’re worse on weed” campaign shows a huge sloth falling asleep in class and being clumsy at dinner alongside slogans such as “when you realise you should have hit the books and not the bong” and "when you're blazed at your family dinner". 

But parodies of the video have gone viral on social media, and even the New South Wales premier Mike Baird, whose department approved the campaign, tweeted his bewilderment at its mammalian stars.

National Cannabis Prevention and Information Centre (NCPIC) director Professor Jan Copeland said in a statement to Fairfax Media that, "using this kind of character is ...likely to have an effect other than those that were intended.”

“Associating a sloth with people being intoxicated may convey a positive appeal to people being intoxicated rather than the intended negative message", she said.

The NCPIC said in a statement they were “not advised of or consulted about creative concept -- the stoner sloth idea” and that “the current Stoner Sloth campaign doesn't reflect NCPIC views on how cannabis harms campaigns should be approached”. The centre’s involvement was limited to “initial basic analysis of other cannabis harms campaigns”, it said. 

A spokeswomen for the campaign said it was created by an external agency, according to the Sydney Morning Herald.

Concerns that the campaign has jeopardised its own anti-marijuana message by using an animal “loveable” and “cool” among teenagers have been voiced by Twitter users.  More than a dozen parody videos have appeared on Youtube during the last day and "stoner sloth" t-shirts are already for sale online. 

But the NSW Department of Premier and Cabinet (DPC) defended the campaign in an email to Mashable, saying: "The Stoner Sloth public awareness campaign has been designed to encourage positive behaviours in young people before bad habits start, and motivate discontinued use of cannabis before they become dependent."

The campaign videos, released this week, feature three sloths called Jason, Delilah and David, struggling with mundane tasks while intoxicated by cannabis.

Delilah cannot finish an exam, in a video entitled "when your mate got blazed but isn't blazing through the exam", while Jason is unable to pass the salt at dinner, in a video called "passing the salt...the struggle is real".  

"Pass the salt" has since been used as an ironic slogan on t-shirts for sale online.

In a further embarrassment, when the Australian internet domain .au is left off the campaign’s web address, users are taken to an online cannabis store, whose tagline is "enjoy every smoking experience".