In December 2010 FMA predecessor the Securities Commission put a freeze on the assets of Hanover director Mark Hotchin and those of two corporate trusts associated with him.
Some of the assets in the trusts have since been released and Hotchin has appealed against the preservation orders against him. The FMA has yet to lay charges against Hotchin.
But the FMA has not frozen the assets of any other failed finance company directors.
Tim Rainey, a lawyer who represents about 2500 former Hanover investors, said it was disappointing the power had been used in only one case.
"I think it is a power that should be exercised far more often than it is.
"It almost appears because [Hotchin] became a bit of a poster boy for the industry that he has been singled out." Rainey said it was often difficult to track down assets as many were held in trusts. "But it is a power that is there. Parliament clearly thought it was necessary."
Rainey said several finance company directors had faced serious criminal cases. But even when found guilty not a lot of compensation had flowed back to investors. There had been some compensation to investors but only through the sale of assets held directly by those sentenced.
"The court hasn't looked beyond to family trusts," he said.
That was difficult for investors to swallow as some trusts appeared to have benefited when the businesses were doing well, receiving dividends if they were also shareholders.
"It's a one-way flow of money. If you speak to investors that is what annoys them," Rainey said.
Shareholders Association chairman John Hawkins said investors continued to be aggrieved at the apparent ease with which failed company directors preserved their assets.
Hawkins said the key difference between Mark Hotchin and the Butlers was that Hotchin was resident overseas and the Butlers lived in New Zealand.