Alcohol ads shown in Australia may be in breach of the advertising code, with many of the actors perceived to be younger than 25, a study has found.

The voluntary Alcohol Beverages Advertising Code requires actors be at least 25 years old and to be clearly depicted as adults, in order to avoid any ambiguity around the legal drinking age.

However a study, published on Friday, found teens who drink heavily often - consuming 11 or more standard drinks per occasion - believe the alcohol ads appeal to their age group because of the attractive, young-looking actors.

Researchers at Curtin University's National Drug Research Institute surveyed the reactions of more than 350 youths aged 16 to 19, after they were shown six current print and online advertisements for different types of drinks, including beer, cider, wine, whiskey and sweet liqueur.

Over half thought that the actors used 'always' or 'usually' appeared to be under 25 years of age, according to the findings published in the Australian and New Zealand Journal of Public Health (ANZJPH) on Friday.

A further 21 per cent thought they 'sometimes' appeared to be under 25.

Most (94 per cent) thought the character used in a liqueur advertisement was aged under 25, while almost 30 per cent thought the adverts were marketed at people less than 18 years old.

The study also found the apple cider and liqueur advertisements were the most likely to be rate as being 'very' or 'quite' appealing.

These beverages were often associated with physical attractiveness and being fashionable, among the study participants.

One 19-year-old female respondent said the drink would make her feel "hot" like the actor in the ad.

Lead researcher Dr Tina Lam, a research fellow at NDRI, says the findings indicate an "urgent" review of the alcohol advertising codes is required.

"This study draws directly on the views of young people, rather than relying on the views of experts or researchers, to understand the way in which alcohol adverts are perceived," said Dr Lam.

"The young people's responses support a large body of research indicating that young people regularly perceive messages that alcohol enhances mood or confers some social benefit," she said.

Fergus Taylor, Executive Director of Alcohol Beverages Australia, says the study of 'heavy' drinkers provides no evidence "at all" that alcohol ads cause underage drinking.

"The evidence based and widely accepted factors affecting underage alcohol consumption are parental and sibling influences and peer drinking behaviour, and the ABAC standards ensure advertising doesn't target or appeal to minors or encourage irresponsible consumption," Mr Taylor said.

He said the latest National Drug Strategy Household Survey actually shows that young people are making better decisions about alcohol.

"82 per cent of 12-17 years olds are now not drinking at all and Australians aged 14-24 have continued to delay starting drinking, up from 14.7 years in 2001 to 16.1 years now," Mr Taylor said.