New Zealand elite soldiers killed six civilians and injured 15 during a raid in Afghanistan in 2010, author Nicky Hager's new book alleges.
Hager is launching his latest book Hit & Run at an event in Wellington.
Hundreds of people have crammed into the Unity Books store, including a large media contingent.
Hit & Run, which was co-authored with freelance war journalist Jon Stephenson, is based on the Security Intelligence Service's (SAS) response to the first New Zealand death in combat in the country.
Soldiers involved in the raid approached the two authors and said they believed they had been involved in war crimes, Hager said at the book launch today.
New Zealand's Defence Minister at the time of the raid, Wayne Mapp, has previously said that no civilians were killed.
Speaking to media after the book launch, Hager said he and Stephenson had discussed the raid with legal experts and they had said there were grounds to suspect war crimes had been committed.