John Button, who served 5 1/2 years in jail after being wrongly convicted of running down his girlfriend in 1963, has asked the State Government for a bigger payout than the $460,000 he was awarded in 2003.
In a letter to Attorney-General Michael Mischin, Mr Button's lawyers claim then-attorney-general Jim McGinty told Mr Button he deserved $15 million for his pain and suffering.
The $460,000 ex gratia payment was "utterly inadequate", lawyer John Hammond said.
Mr Hammond compared the payout to the $3.25 million given to Andrew Mallard in 2009 for his 11 1/2 years behind bars though innocent of murdering Mosman Park jeweller Pamela Lawrence in 1994.
Mr Mallard was released in 2006 and another man was later identified as the likely killer.
Mr Button served his sentence but was not exonerated until 2002.
"Mr Mallard received some $3.2 million ex gratia for being dubbed a murderer for 14 years," Mr Hammond said in the letter.
"Our client has received only $460,000 for being dubbed a murderer for 39 years. While we understand there is no 'tariff' applied to ex gratia payments, we nevertheless believe that this comparison demonstrates the manifest inadequacy of the payment our client received in 2003."
Last month, Mr Mischin replied to letters Mr Button sent in 2009 and 2010. He refused the request for more money and said Mr Mallard's payout was "not relevant".
He said the circumstances were unique so it did not follow that one ex gratia payment had any bearing on another.
"In most cases where ex gratia payments are made, the compensation takes the form of a contribution towards the legal costs and disbursements incurred by the accused person," he said.
"In other cases, of which your 2003 payment is an example, much larger payments have been made. Each case is different."
Mr Hammond's reply was sent last week. He said yesterday 40 years of Mr Button's life had been stolen by a flawed guilty verdict.
"The effects of the payments to Mr Mallard and Const. (Matthew) Butcher (a police officer who received $3.3 million for injuries when hit with a flying headbutt while on duty) highlight the inadequacy of John Button's payment," Mr Hammond said.