Fish oil pills may be investigated in Australia after research showed most of the bottles sold in New Zealand carry false claims.
Only three of the 32 fish oil capsule brands tested by researchers from Auckland University and Newcastle University contained the amount of omega-3 fatty acids declared on their labels.
The supplements had on average 68 per cent of the claimed content, according to the study published in Scientific Reports.
Half of the products tested were encapsulated, labelled and marketed from Australia, said University of Auckland's Wayne Cutfield.
A Therapeutic Goods Administration spokeswoman said the TGA is reviewing the study to see if any action is required.
There are 683 products containing fish oil on the Australian Register of Therapeutic Goods, she said.
And fish oil-containing products may be sold in Australia as foods, which are not regulated by the TGA, she added.
The TGA will consult with Food Standards Australia on this.
"The TGA monitors compliance with quality standards through the listed medicine compliance program.
"Where a compliance issue is found, appropriate regulatory action is taken."
Steve Scarff from the Australian Self Medication Industry said the New Zealand study was not relevant to Australia.
"Fish oil products are highly regulated in Australia," Mr Scarff said.
"Australian consumers can be confident that the fish oil products they buy here contain the ingredients listed on the label," he said.
"The products that are coming out of Australia into New Zealand would be under the New Zealand dietary supplements regime rather than the Australian Therapeutic Goods Administration regime," Mr Scarff said.
The list of brands tested by the researchers has not been released.
The researchers also detected worryingly high levels of oxidisation in the supplements, which can reduce the efficacy of the omega-3 fatty acids.
The long-term health implications of high oxidation products is not known.
The Australian Competition and Consumer Commission would not comment, referring back to the TGA.
