Marinker's extensive voice credits include numerous BBC radio plays and poetry readings, from Dirk Maggs' Batman: Nightfall (as Bane) to a man tortured by his own tax forms in the 2006 play The Wire. In animation, Marinker has dubbed several Japanese animated series, and dubbed Julius Caesar in the live-action film Asterix and Obelix vs. Caesar. A prolific narrator of audiobooks, from Shane to The House of Seven Gables, he has also appeared on camera in the movies Nightbreed, Judge Dredd, and United 93. Marinker is also a founding member of the Godot Company, a theater group devoted to performing the work of Samuel Beckett. Other members included fellow Labyrinth voice Anthony Jackson.