An investor in the failed Lombard Finance company says the Prime Minister has devalued knighthoods by allowing a former director to keep his.
The company collapsed in 2008, owing $111 million to 3600 investors.
In 2012, former directors Sir Douglas Graham, William Jeffries, Michael Reeves and Lawrence Bryant were found guilty of making false statements in a company prospectus.
Sir Douglas was sentenced to six months' home detention and 200 hours of community work.
The Prime Minister said on Friday he has spent two years deciding whether Sir Douglas should keep his knighthood.
John Key decided it should be retained because it was conferred to him for his Treaty settlement work, rather than for anything financial.
Mr Key says he knows the decision will be tough for out-of-pocket investors to accept. However, he says there is no international precedent for removing an honour where the indiscretion was in an area different from that in which the honour was conferred.
Mr Key says Sir Douglas may have returned the honour, but the decision was taken out of the former minister's hands because, as Prime Minister, it was his responsibility.
But Lombard investor Paul Wah, who lost a quarter of his retirement savings, says the decision leaves knighthoods devalued.
"The message is, that the value of a knighthood has been diminished. John Key has put his valuation in terms of what he did as far as (Treaty) negotiations are concerned, and I'm looking at Douglas Graham from the point of view as the chairman of Lombard."
Last week, the Supreme Court turned down the four directors' applications to appeal against their convictions, but said they can appeal against their sentences.
