The Shareholders Association says an auditor's report which questions the future of Allied Farmers is another blow for former Hanover investors.
PricewaterhouseCoopers says it has not been able to obtain sufficient evidence to decide whether Allied Farmers can continue operating as a going concern.
Last year investors in the troubled finance company agreed to swap their debentures for shares in Allied Farmers.
The Shareholders Association says the auditor's comments suggest that Allied Farmers has serious problems.
Chairman John Hawkins says it will be particularly disappointing for former Hanover investors, who he feels will be very worried about their investment.
He says the challenge for Allied Farmers will be whether it can generate sufficient cashflow, which he believes will be a difficult task.