The legal aid bill for David Bain was the highest for an individual in New Zealand at $3.3 million.
Bain was convicted in 1995 of murdering his family in Dunedin and was acquitted in a 2009 retrial.
The last High Court retrial cost $2.3 million, the Otago Daily Times reported. Of that lawyers' fees were $1.4 million.
The figures were released under the Official Information Act.
Bain is not receiving legal aid to assist with an application for compensation, the newspaper reported.
Bain said in a speech to an international justice conference in Perth last month that his whole family had been killed by shots to the head in various states of wakefulness.
"In May 1995, not only had I lost my family, all I owned, all I had known of life in New Zealand but I had been charged and convicted of the worst crime possible. New Zealand's system had decided I was guilty of taking the lives of all those I loved," he said.
He said he never entertained the thought that he would be convicted.