Statutory managers controlling the affairs of South Island businessman Allan Hubbard have frozen funds in another investment firm he controlled.
The Government placed Mr Hubbard and his wife Margaret into statutory management along with seven charitable trusts and Aorangi Securities on 20 June.
Richard Simpson and Trevor Thornton, of Grant Thornton, say their job has become more complex since learning of another business, Hubbard Management Funds.
They estimate the investment management business is worth about $70 million, but say they can't give an updated value because its accounting systems are inadequate.
They say the company had no formal disclosure document, and Mr Hubbard recorded clients' investments in hand-written cashbooks and journals, which were then posted to an electronic ledger account.
The fund will remain frozen until they bring the accounting up to date.
Meanwhile, they are warning some of the 400 investors in Aorangi may be at risk, because many of the company's loans were to farm businesses, which rank behind secured bank loans.
One of the charitable trusts being investigated, Te Tua Trust, borrowed money from Aorangi and some of the interest-free loans it made to business people are in arrears.
The statutory managers say they may have to get help from the court to sort out which investors get priority, and which ones are secured.
Aorangi Securities is also under investigation by the Serious Fraud Office, following a Companies Office report that found irregularities among some $134 million in loans.