Posthumous Acting? 

While I'm sure it is just a case of poor wording, the following entry from the CAST section of The Princess and the Goblin would seem to indicate that one of the voice actors made his contribution four years after he'd died!
 
Roy Kinnear - Mump. This was Kinnear's final role after his death on September 20, 1988. 

Even the Wikipedia bio page for Mr. Kinnear (who was a terrific character actor) shows the same date for Princess but gives no explanation....

173.219.118.86