A study of smokers in Australia suggests there is "no evidence" that the introduction of 'plain' cigarette packaging has changed the way people buy cigarettes.
Researchers writing in BMJ Open found no increase in the use of illegal tobacco and no sign of cheaper brands flooding the market.
They surveyed 2,000 smokers before and after the laws came into force in 2012.
Tobacco companies said the survey was limited and not statistically robust.The study, from the Centre for Behavioural Research in Cancer in Melbourne, also found no evidence of small retailers, such as newsagents, convenience stores and corner shops, being hurt by the change.
Opponents of 'plain' or standardised packaging in Australia and the UK, such as the tobacco industry, had previously predicted that this would happen.
Standardised packaging of tobacco products was introduced in Australia in December 2012. It was the first country in the world to do so.
Since then, all tobacco products have to be sold in standardised dark brown packaging with large graphic health warnings. There are no tobacco industry logos, brand imagery, colours or promotional text on the packaging. Brand and product names are printed in small text.
Study participants were identified using an annual health survey of adults from the Australian state of Victoria.
They were contacted by phone towards the end of 2011, 2012 and 2013 and asked specific questions about their cigarette purchasing habits.
In all years, the use of low-cost Asian brands among regular smokers was found to be "very low" at under 2%. This figures did not significantly increase between 2011 and 2013.
The percentage of smokers who had bought unbranded illegal tobacco in the past 12 months was found to be between 4 and 5%, which did not change significantly between 2011 and 2013.
In 2013, 2.6% of smokers said they had bought at least one pack of cigarettes which was not packaged according to the new legislation in the past three months.
But the study said there were "too few cases to estimate percentages" of those buying contraband over a three-month period.
Simon Clark, director of the smokers' group Forest which runs the Hands Off Our Packs campaign, said other reports had come to different conclusions.
"A KPMG report found clear evidence that illicit trade has grown since the introduction of plain packaging in Australia. That report was based on hard data not anecdotal evidence.
"A recent investigation by a national newspaper suggested that criminal gangs in the Far East can't wait to profit from increased sales of counterfeit cigarettes in the UK if plain packaging is implemented here."
"The limited telephone survey published in the BMJ only covers one Australian state and does not provide a statistically robust assessment of the impact on the illicit market and retail trade."
However, Hazel Cheeseman, director of policy and research at Action on Smoking and Health (ASH), said the study provided proof that the tobacco industry's claims about the effect of standardised packaging "are just not true".
"Standardised packaging is helping to cut smoking in Australia. The findings should reassure the UK government that standardised packaging makes it a policy whose time has come."
In April, the UK government agreed to introduce plain cigarette packaging after an independent report concluded it was "very likely to have a positive impact" on public health and stop children from starting to smoke.
But, at present, the Department of Health in England has not yet made a final decision on whether plain packaging will be implemented.
The latest consultation on packaging will apply to England and Wales. Northern Ireland has indicated it will follow suit with any legislation and Scotland already has plans to introduce plain packaging,
Campaigners are urging the government to speed up plans to ban branded cigarette packets.
Source : https://www.bbc.com/news/health-28966048