Graeme Samuel, Chairman of the Australian competition and Consumer Commission (ACCC), said the company had admitted that certain claims on its labels, including "the blackcurrants in Ribena contain four times the Vitamin C of oranges" , were unsubstantiated.
Companies are coming under increasing pressure over their use of nutritional claims with GSK allegedly facing possible prosecution over a similar labelling issue in New Zealand courts.
Though welcoming the company's decision to report its own inaccuracies, Samuel reiterated the need for processors to ensure any health benefits were factually backed.
"It is extremely important that companies use appropriate calculation methods when making claims about the contents of food or beverage products, especially when those claims relate to nutrition," he said.
As a result of its own findings, GSK will co-operate with the ACCC over measures to prevent further inaccurate health claims.
This will see notices for stores detailing potentially misleading claims, as well as refraining from the use of any future nutritional promotions that cannot be substantiated.
Despite these measures, GSK's case is likely to lend further weight to a report produced earlier this month for the Food Legal Bulletin, underlining deficiencies in current nutritional labelling within the country.
In the report, which was written for food lawyers and consultants, lead author Professor Joe Lederman expresses concern over the legislation set out by the Australia New Zealand Food Standards Code.
Under current requirements, all packaged food sold in the two countries must come with a Nutrition Information Panel (NIP), which can be obtained through one of four information sources.
These sources range from laboratory analysis and food composition tables to a nutrition panel calculator on the Australian and New Zealand Food Standards website, though the report is unsure of their true effectiveness.
"All such data irrespective of its source would be subject to being an average or mean of data accumulated over many years from many analyses," states the report.
"For some inexplicable reason, the law always assumes that this data has been derived from the same named biological source, even though this assumption is a fiction."
With nutritional content likely to vary from individual weather conditions and farmers' treatments, the report questions the NIP system's effectiveness in accurately judging a products nutritional value.
"Since it is mandatory by law to require that the Nutrition Information Panel accompany all food products on the label of packaged food or be available on request for the buyer of unpackaged food, what is the point of having the law exist at all?" concludes the report.