The corporate watchdog quietly dropped a case against 10 senior Queensland racing officials referred for investigation by a commission of inquiry in 2014.

The Australian Securities and Investments Commission found insufficient evidence to proceed against Bill Ludwig, the Labor powerbroker and a former board member of Racing Queensland, nor other board members and executives including chairman Bob Bentley.

Labor powerbroker Bill Ludwig was a board member of Racing Queensland. Credit:Glenn Hunt

The Newman LNP state government's three-month inquiry into the racing industry was chaired by retired Supreme Court Justice Margaret White, who was in July appointed joint head of the probe into youth detention in the Northern Territory.

Justice White found a raft of suspected breaches of the Corporations Act by Mr Ludwig, Mr Bentley and others.