"The Australian Competition and Consumer Commission wants to see an overall improvement in trade practices law compliance at every level of the industry - from packaged juices in supermarkets and convenience stores through to the exotic juice bar blends," said chairman Graeme Samuel.
"The ACCC is particularly concerned about the growing use of health claims widely used to promote fruit juice, smoothie and related juice products being sold in juice bars.
"These claims about certain ingredients may not exist, cannot be substantiated or, in fact, may adversely impact on a consumer or their diet," said Samuel, adding that the commission has written to juice bar franchisors to alert them of its concerns and remind them of their fair trading obligations.
The ACCC's move comes as analysts predict Australia's fruit juice industry will explode over the next few years, led by the strong emergence of juice bars.
Juice bars are expected to double their current $150 million (€90.5 million) turnover in 2005, taking their share of Australia's $1 billion juice industry to 30 per cent.
John Martin, of the ACCC, said the whole sector had grown rapidly in recent years with around 200 different, fresh juice products now available in some supermarkets.
He said the dynamic growth had made competition fierce, increasing the "tendency to 'push the envelope' over misleading labelling and product descriptions".
Martin highlighted a variety of tough actions the ACCC had already taken in the juice sector over the last few years.
This includes: legal action against Cadbury-Schweppes for depicting real fruit on packs that was not in the products, and the Outback Juice Company for claiming its product contained 100 per cent fresh orange juice without mentioning the potential for added sugar.
Now, the ACCC's new focus on fruit juice could spark similar investigations in other markets if it finds consumers are still being misled.
Fruit juice has seen rapid growth across both developed and emerging markets thanks to consumer health trends, and major drinks producers such as PepsiCo and Coca-Cola have announced plans to expand in the sector.
As a result, health claims on juice products have become an issue. The UK's novel foods committee has just announced its initial approval for Coca-Cola to market a new juice containing plant sterols as a cholesterol-lowering product.
UK sales of chilled, high quality and natural juice have increased by 60 per cent to some £768 million (€1.1bn) over the last two years, according to market research group Mintel.
Average daily fruit juice and nectar consumption in the UK was put at 50g per person by the country's Advisory Committee on Novel Foods and Processes in January. The committee said other EU countries had a similar rate, except for Germany where the average was 111g.