An Australian state-owned energy company has been asked to explain why it conducted cloud-seeding over Tasmania's Derwent Valley the day before deadly flooding.
The catchment flooded on Monday near Ouse in the southern part of the state, where the search continues for a missing farmer.
In the state's north, one person was killed and another remains missing.
Cloud-seeding is a technique used to increase rain to bolster dams, and involves the addition of a substance to suitable clouds to encourage the growth of ice crystals or raindrops.
Premier Will Hodgman said he was told Hydro Tasmania authorised the action on Sunday morning in the Upper Derwent catchment, even though heavy rainfalls were forecast.
Mr Hodgman said the decision was difficult to fathom at face value and Australia's energy minister has asked the company for an urgent explanation.
Hydro Tasmania confirmed it flew a cloud-seeding flight the day huge storms approached the country's east coast.
Documents show the flight took place on Sunday morning while there were flood warnings in place in the north.
The flight seeded clouds for more than an hour and a half just north of Great Lake, one of the largest water storage dams in the state.
The flight was targeting the Upper Derwent catchment, which mainly feeds water to several hydro electric dams which lie downstream.
The company was not commenting further, with a spokeswoman saying it would be inappropriate.
"At this point Hydro Tasmania is not in a position to provide more information," she said.
"Experience suggests that in the aftermath of a severe natural disaster such as this some form of government inquiry follows.
"In light of the unfortunate death of one person, and with grave fears for two people still missing, there is likely to be at least a coronial inquest."