A member of the group who hosted Nicky Hager in Nelson said it was the biggest turn-out they've ever had.
Spirited Conversations Group member Barry McKee said about 100 people turned-out last night.
McKee said the audience was sympathetic towards Hager unlike what he had heard on talk-back radio.
McKee added he had not bought the book yet but did find Hager very interesting.
The book, Hit and Run, was co-written with Jon Stephenson.
The New Zealand Defence Force has reiterated their 20-11 statement following the launch of Nicky Hager's book.
The book claims John Key allowed a SAS raid to go ahead which injured 15 and killed six civilians.
Speaking to RNZ before his book launch, Hager said the response mainly affected women, children and elderly, with a three year-old toddler dying in her mother's arms.
The Defence Force re-posted their initial statement saying these claims continue to be unfounded.
Hager said there are strong grounds to suspect what happened in 20-10 was indeed, a war crime.
Hager will talk at the University of Canterbury on the sixth of April.