Ross liquidators want $21m
Director David Ross stole $115m from at least 700 investors.
But other clients managed to withdraw their investments, and fictitious profits, before the scheme collapsed.
Nearly $10m has been recovered from 54 investors who settled claims against them before a Supreme Court decision in May on a test case brought against Wellington barrister Hamish McIntosh.
Now Ross liquidators PwC have written to 160 investors, asking them to settle claims against them worth $21.6m.
They have until Friday to make a decision, or face possible recovery action.
Earlier reports from PwC had suggested fictitious recovery claims could reach $40m - and could have been $90m if the Supreme Court decided principal should be paid back as well.
But the Supreme Court decided that McIntosh could keep his initial $500,000 investment.