In 2008 he co-directed with his wife and business partner, Sara Stretton, "The Third Richard" a feature-length documentary where he tells the story of his grandfather, a Jewish German composer whose music was banned by the Nazis, rejected in New Zealand and is now being rediscovered.
In 2008 and 2010 he directed children's drama series, Paradise Cafe for CBBC, Emu for CBeebies and Time Trackers for Seven Network Australia.
In 2005 Mulheron co-wrote, directed and produced the comedy series Seven Periods with Mr Gormsby, about an aging reactionary schoolteacher who gets a job working in a high school.
He has also worked on plays with New Zealand novelist and scriptwriter Stephen Sinclair, and writer/cartoonist Tom Scott, another of the Gormsby co-writers.
Mulheron's career has seen him host a television show about automobiles, AA Torque Show, play the part (and piano) of Shostakovich in "Masterclass" at Circa Theatre and play a traumatised hippopotamus in Peter Jackson's Meet the Feebles, for which he was nominated for an award for best female performance.