Duncan, who graduated as a civil engineer from the Ballarat School of Mines, worked for the federal government on diverse projects including the atomic bomb testing facilities at Woomera, South Australia, and the construction of a hydropower station and dams in Papua New Guinea during the 1950s and 1960s.

He started in the mining industry in the early 1970s and had a long career, particularly in the coal industry, having developed numerous coal mines in Australia and internationally.

Duncan was also the chairman and major shareholder of Felix Resources prior to its takeover by Yancoal Australia. 

He was also involved in the engineering and construction of major public works including the High Court of Australia, National Library and the National Gallery in Canberra.

In a dramatic turn of events in 2015, the New South Wales corruption watchdog overturned its own findings that directors of Cascade Coal, including Duncan, were guilty of corruption.

As part of a legal fall out between a case brought against its crown prosecutor, the Independent Commission Against Corruption said that on the basis of legal advice, and in light of the High Court ruling on the case of crown prosecutor Margaret Cunneen, "it has no arguable basis or option to resist" court orders overturning the findings.

Duncan and fellow directors John McGuigan, John Atkinson, and Richard Poole were initially found by ICAC to have acted corruptly by concealing from NSW officials the involvement of the notorious Obeid family in a coal tenement in NSW's Bylong Valley.

Former NSW mines minister Eddie Obeid owned a farm over where the mine would have been located.

The directors had launched NSW Court of Appeal proceedings to have the findings against them overturned, after losing their case in the Supreme Court.

White Energy chairman Graham Cubbin said Duncan's knowledge and input had been invaluable particularly in White Energy's successful litigation against Indonesian group Bayan Resources in the Singapore International Commercial Court over a failed joint venture.

White Energy CEO Brian Flannery said: "Having worked with Travers substantially since 1973 on many different mining projects, I have come to respect his engineering and business abilities".

Duncan will continue his involvement with White Energy as a substantial shareholder.