There is little doubt from one expert that what's described in Nicky Hager's new book is a war crime.

The "Hit and Run" book claims the SAS killed six civilians and wounded 15 more during retaliation raids in 2010.

Boston College war crimes expert Devin Pendas told Rachel Smalley in order to count these civilian kills as war crimes, there needs to be proof of intent.

"The fact that allegations are that the children were killed are the pieces of evidence the prosecution really would want to emphasise because no one is going to say 'I thought that 3-year-old was an insurgent.'"

However, Pendas believes that everything else seems to be clearly illegal.

"I think that the facts that are alleged - if those facts turned out to be true, I think you could make a pretty strong case that these constituted war crimes."

LISTEN ABOVE AS DEVIN PENDAS SPEAKS TO RACHEL SMALLEY