The Enemy of the World - S5-E4
Audio problem: In episode 3 of this story it is noticeable that practically every sound in this episode has been re-dubbed and as a result is out of synch - sometimes quite badly. An example is when Milton Johns has his thugs break into Giles Kent's trailer - there's a three-second lag between the breaking of the plates and the sounds they make. (This may be simply due to the only surviving copies in the BBC Archives being these "badly dubbed" ones, recovered from obscure sources).
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB