Dempster began his career as a cadet on the Maryborough Chronicle in Queensland, and moved to Brisbane's Telegraph, where he became the paper's chief political reporter.
The inquiry, headed by Tony Fitzgerald QC, ran from 1987 to 1989, and Dempster's re-enactments and analysis on the national 7.30 Report program brought the issue to a wide audience.
In 1990, Dempster moved to Sydney to become the 7.30 Report's NSW presenter, heading a national investigative unit for the program in 1995 and covering the Wood Royal Commission into police corruption south of the Tweed.
[1] Dempster made the announcement at the end of 28 November's Friday night's 7.30 NSW program, a show which was being axed under the ABC cuts strategy outlined by managing director Mark Scott that week.
ABC director of news Kate Torney said Dempster's departure was a "huge loss" and described his coverage of corruption in Queensland and New South Wales as "exemplars of the fearless and forensic journalism which has earned Quentin the respect and admiration of his peers and the gratitude of his viewers".