Police say the 69-year-old Killarney local was moving cattle to higher ground at a property along the Condamine River when a wall of water washed his car away around 8pm on Wednesday.

Emergency services searched for the man for hours before he was found dead inside his vehicle about 100 metres downstream at 12.20am.

A major flood watch was issued for Killarney on Wednesday night after a severe storm thundered more than 170mm on the region in an hour.

Federal Member for Maranoa and Emergency Management Minister David Littleproud has offered his condolences to the family of a Killarney man killed in floodwater overnight.

"I am shocked by the news this morning, and I offer my deepest condolences to the family, Killarney is a close knit community and this has had a devastating affect on the community," Mr Littleproud said.

"Tragically Killarney received significant rain over the last 24 hours, causing dangerous flash flooding in the area."