The Government has so far paid $400,000 to employ a Canadian judge to evaluate whether David Bain should receive compensation, Radio New Zealand reports.
Documents released to Radio New Zealand under the Official Information Act show retired Canadian Supreme Court judge, Justice Ian Binnie, has been paid almost $315,000 excluding GST, as well as almost $34,000 for travel and expenses.
Justice Binnie was asked by the Government last November to recommend whether Mr Bain should get compensation, although Cabinet will ultimately decide whether he does.
Mr Bain served almost 13 years in prison over the murder of his parents and three siblings in 1994, before being acquitted at a retrial in 2009. He could be looking at a pay-out of almost $2 million, should compensation be awarded.
Justice Binnie has been paid $450 an hour, which the Ministry of Justice told Radio New Zealand was comparable to the rate paid to New Zealand Queen's Counsel when considering compensation claims.
Radio New Zealand reported Justice Binnie had travelled to New Zealand four times in the past 11 months in order to interview people involved in the case, including Mr Bain.
Justice Minister Judith Collins received Justice Binnie's report last month, but said it would not be released until Cabinet had decided whether to pay compensation.
However the Herald last month learned Justice Binnie believes, on the balance of probabilities, Mr Bain is innocent.