New statistics from the ABS say illegal drugs add about $6 billion to the Australian economy every year, with cultivation shaping up as a rapidly-mushrooming domestic market.

Australian Bureau of Statistics researchers have been investigating the massive market for illegal substances in order to update their gross domestic product estimates. The ABS has found illegal drugs account for about 0.4 per cent of the total economy – no small margin for an industry free from tax and regulation.

Statistic show around $3.6 billion is spent on marijuana per year; in 2010 Australians spent $1.1 billion on amphetamines, $585 million on cocaine, $520 million on heroin and $200 million on ecstasy. The Bureau has found Australia’s heroin habits are dropping, or the price is, with a 19 per cent reduction over the past five years.

The cultivation of marijuana contributes about $1 billion to the agriculture industry every year, while around $4.5 billion is made through manufacture, wholesale and retail sales.

It estimates drug seizures by authorities take a small scrape off the top of the total market, depriving consumers of only about $80 million worth of product per year.