Wastewater testing found 2 million doses taken in a single week in April, up around 15% on last year.
But Casey Costello, the minister in charge of tackling transnational and serious organised crime said weekly consumption fell in June to 27.7kg, 18% lower than the average over the previous four quarters.
"Around the world, you know, huge changes in the drug supply are happening very quickly, and big increases in drug consumption," Drug Foundation executive director Sarah Helm told Mike Hosking.
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