In February 1999, he made his K-1 debut against Japanese legend Musashi at K-1 Rising Sun '99 and lost via technical knockout after being knocked down three times in the third round.

[4] The end of 2012 saw Duncan lend his voice to one of his most recognised roles to date in the short comedy film The Greyness of Autumn.

[5] Duncan voiced the character of Danny McGuire, an ostrich living in Glasgow whose life is suddenly turned upside down when he loses his job and his girlfriend in the same day.

[8] Duncan's performance was widely praised with John McArthur of MovieScramble writing "The hook at the start of the film is the voice of Danny.

"[9] In 2013 he played the role of Officer White opposite Jack O'Connell in Starred Up,[10][11] a feature film directed by David Mackenzie.