A top government minister says there's already been an inquiry into the raid at the centre of Nicky Hager's new book.

The book titled "Hit and Run" alleges six civilians were killed in an operation involving the New Zealand SAS in Afghanistan in 2010.

But Finance Minister Steven Joyce told Mike Hosking Mr Hager "only ever talks to one side of the story."

"He never talks to anybody else, and then he makes major accusations and sweeping statements."

Mr Joyce said there was an Afghani inquiry at the time, and he doesn't see the need for another.

"Defence have spoken up overnight and said look, we've been through all of this, there isn't significant new information in the book from their perspective and they stand by the results of the inquiry at the time."

LISTEN ABOVE AS FINANCE MINISTER STEVEN JOYCE AND LABOUR MP STUART NASH SPEAK WITH MIKE HOSKING