Supporters of Alan Hubbard have complained to the ombudsman about the Serious Fraud Office's investigation of the financier.
Mr Hubbard and his wife have been placed under statutory management, along with Aorangi Securities and several trusts, as the Serious Fraud Office investigates what it says are irregularities in Aorangi's loans.
One of his supporters, Paul Carruthers, is calling for more investigation into a potential conflict of interest with a Securities Commission member, Simon Botherway.
The regulator says it is satisfied there is no conflict of interest after Mr Botherway revealed a company belonging to his brother was put into receivership by Mr Hubbard's South Canterbury Finance.
However, Mr Carruthers says Mr Botherway should be stood down.
He and three other people are lodging a formal complaint to the ombudsman.