Australia's cigarette trade is being propped up by the exploitation of children, with new figures revealing more than $16 million of tobacco grown using cheap child labour is being imported every year.

An analysis of United Nations trade data shows that almost 3000 tonnes of tobacco was imported last year from countries using child labour to cultivate crops.

Anti-smoking group ASH Australia, which compiled the figures, warns that children as young as five are being paid a pittance to work in the tobacco trade, and face serious health risks from nicotine poisoning.

ASH chief executive Anne Jones said while most smokers now knew the health risks, many would be unaware their cigarettes largely came from countries such as India, the Philippines, Thailand and Malawi, where child labour was rife.

''Many are being taken out of school and some are working up to seven hours a day. In many countries they're earning less than a dollar a day, so there's a huge amount of exploitation,'' she said.