It is a little known fact that Tasmania makes a roaring trade growing opium; now demand for the lucrative crop has pushed companies to look at expanding onto the mainland.

Global demand for pain-killing derivatives of the plant best known for being made into heroin is increasing, with codeine and morphine sales reportedly on the rise.

Tasmanian poppy barons currently have exclusive rights to grow opium, producing about half the world's legal supply. Breeding, contracting and harvesting the plant is the responsibility of just three companies, all of which are reportedly looking to Victoria to sew more seeds.

Global pharmaceutical company Glaxo-Smith-Kline first planted trial poppy crops in Victoria in 2009, but this year will conduct its first extensive trials. The Victorian Department of Health has recently approved GSK to conduct six small-scale trials in northern and western parts of the state.

The Health Department has approved a research trial by another poppy processor, Tasmanian Alkaloids. The third company active in Tasmania, TPI Enterprises, has an application pending approval too.

Poppy Growers Tasmania president Glynn Williams says there is still plenty of potential for industry expansion within Tasmania: "While Tasmania has met and achieved enormous growth in the last 10 years, we believe we can actually do that again, here and contain that very potent crop to Tasmania... between 2018 and 2023 there might be some advantage to Tasmania to see some growing elsewhere, but it's not here now."