Hamilton this month challenged the length of his jail sentence of four years and nine months, with his lawyer telling the Court of Appeal the sentence should have been "significantly lower".
This was because the starting point the judge took of five years in jail should have been three years and the reduction Hamilton received for his "extensive community involvement and previous good character" was far too small.
Hamilton's lawyer Jonathan Krebs argued the trial judge had not adequately separated Hamilton's role in the offending from Belgrave directors Stephen Smith and Shane Buckley - both of whom were also jailed on theft charges.
While Mr Krebs said the directors were the principal offenders, Crown lawyer Nick Williams argued in some ways Hamilton was more culpable than them.
The Court of Appeal, in a decision given by Justice John Wild yesterday, said the five-year sentencing starting point "appropriately reflected Mr Hamilton's real involvement, as a solicitor, in the dishonest related party lending by Belgrave".
On the level of the discount for past character, the appellate court said Hamilton had little credit left, given the offending went on for three years and that unrelated misuse of client funds led to him being struck off as a lawyer.
The Court dismissed the appeal.
During Hamilton's High Court Trial, an SFO forensic accountant said Belgrave made around $12 million of loans to entities effectively controlled by property developer Raymond Schofield.
Those loans breached Belgrave's debenture trust deed, the rules dictating the terms and conditions between investors and the company accepting the funds.
For the theft charges Hamilton was found guilty of, he was accused of helping Schofield, Smith and Buckley with those loans and was therefore a party to their offending of theft by a person in a special relationship.
For those charges to stack up, the Crown had to prove Hamilton helped with the breaches, was aware of the offending and intended to assist with it.
The Crown's main allegation was that Hamilton assisted by receiving a portion of the loans in question into DAC Legal's Trust account.
Justice John Faire said when delivering his verdicts that Hamilton assisted with the offending by carrying out instructions to execute related-party loans.
The judge also said Hamilton had knowledge of the offending: "The surrounding circumstances make it entirely implausible that Mr Hamilton was not aware of the offending.
"Having found that Mr Hamilton had the relevant knowledge of the offending, I am satisfied beyond reasonable doubt that he intended to assist in the offending."