In original terms, mineral exploration expenditure dropped 20.1% or A$151 million to $602.1 million, with exploration for base metals down 28.8%, or $57.5 million.
Brownfields exploration dropped 16%, while greenfields exploration dropped 26.1%.
Metres drilled dropped 17.3%, comprising a 12.3% fall for areas of new deposits, and 19.9% drop in areas of existing deposits.
Industry groups the Association of Mining and Exploration Companies and the Minerals Council of Australia have called for more government support for explorers in wake of the COVID-19 pandemic.
"Today's figures show that without greater cost relief or financial assistance, there will be consequences for the exploration industry in Australia, and for the ability of Australia's mining industry to identify and develop new major projects ready for investment to support Australia's economic recovery," AMEC CEO Warren Pearce said.
"We anticipate the next quarter's statistics will more accurately reflect the full impact of COVID-19 on our industry."
MCA CEO Tania Constable said the "alarming" figures showed the federal government needed to do more to attract exploration investment, grow jobs and support regional communities.
"Lower prices for many commodities and restrictions on regional movements in key mining areas are likely to result in further falls in the current quarter," she said.
"To retain its international competitive advantage in geoscience, boost exploration activity and incentivise job-creating mine development in new regional areas, the government should extend and expand its investment in early-stage exploration programs in emerging mineral provinces in regional Australia."
Constable called for the government to continue to fund programs like Geoscience Australia's Exploring for the Future program as a matter of priority.
"This investment will deliver significant economic benefits. A recent independent review of Exploring for the Future by ACIL Allen showed the net benefit to taxpayers of the $100 million program could be as high as $632 million," she said.
"Investment in exploration will deliver economic returns for future generations while supporting exploration jobs through the COVID-19 pandemic and during Australia's recovery."