Ben Roberts-Smith defamation case focuses on who shot dog as two witnesses recant evidence

The question of who shot the dog was a main issue in Ben Roberts-Smith's defamation trial. (AAP: Bianca De Marchi)

In a high-stakes defamation case involving a decorated war veteran and allegations of unlawful killings in Afghanistan, another question has recently taken prominence: who shot the dog?

The mystery is linked to an allegation against Ben Roberts-Smith outlined in court documents from Nine Entertainment, the publisher of newspapers he's suing in the Federal Court, which the Victoria Cross recipient denies.