"In our view, the material released to date establishes credible allegations that during the course of their attack on these villagers in 2010 the NZ defence forces breached fundamental principles of both NZ law and international law, including war crimes and violations of the right to life."
The law firm has asked Attorney General Chris Finlayson and Prime Minister Bill English to clarify what happened in Afghanistan, saying there were too many "different versions" of events.
The lawyers believe the book and say Defence Force denials have misled the public. The claim no civilians were killed is a "cover up", they say.
They are seeking a judicial review of the government's referral of the matter to the Chief of Defence and his declining of an independent inquiry of the matter, claiming the government's decision to refer the matter was wrong and the Chief of Defence stance on the inquiry was fundamentally flawed.
The Defence Chief was "the wrong person to make the decision", the lawyers said, as he had "already taken the position that the allegations were unfounded" and was therefore "biased".
Manning said the alleged victims were "relieved" that the next step had been taken.
"They have suffered a lot and continue to suffer due to the devastation of that night," Manning said.
The lawyers said their clients had "a human right to an inquiry".
They are representing three groups of applicants from the villages in the area of the event.
They will seek suppression of their names.
The Government and Defence must now respond to the proceedings.