[1][2] In 2012, he pleaded guilty to accessing child pornography and served four months of a five-month jail sentence.
[4][9][10] In June 2010 he went on unpaid leave and production of Collectors was temporarily suspended when he was charged with one count of accessing child pornography.
Production of Collectors resumed in July without Muirhead, and repeats of episodes featuring him were pulled from the ABC's schedule.
[3] A scandal involving the use of video material featuring Muirhead in New South Wales public schools occurred in 2019.
[23] A video featuring Muirhead presenting Collectors had been used as a teaching resource for an unknown number of distance education students across New South Wales and formed part of the material in the Year 10 History course that was sent out to distance education students studying through Camden Haven High School on the NSW mid-north coast.