Sports supplement users in New Zealand are being urged not to take the product Oxy-Elite Pro, after reports of a link to non-viral hepatitis.
The Ministry for Primary Industries is working with food safety watchdogs because the liver condition has been linked to the use of the sports supplement in the United States.
Ministry acting director-general Scott Gallacher says there are no reported cases as yet in New Zealand.
However, Mr Gallacher says the situation is still unfolding and risks cannot be taken, which is why he has issued the precautionary notice.
He says one of the first things to find out is just how widespread is the use of Oxy-Elite Pro in New Zealand.
Mr Gallacher says he's concerned the use of the supplement could be widespread in New Zealand, given it is also sold online.
Don't take 'fat burning' pills says expert
A medical researcher says a food safety warning for a dietary supplement highlights the risk of weight loss pills.
Professor Shaun Holt from Victoria University says the warning demonstrate the potential danger of so called fat burning pills.
"I wouldn't recommend any products in this class whatsoever. If you want to lose weight simple old fashioned diet and exercise is the way to go.
"These products, and others like them throughout the years have been linked with all sorts of health problems. So I think certainly the risks outweigh any potential benefits."
Professor Holt says its particularly risky to buy dietary supplements online.