Auditors who advised the Presbyterian Mutual Society in the North, which has encountered serious financial difficulties, are to be investigated by an independent regulator.
The Accountancy and Actuarial Board will examine events, which led to the Society being placed into administration last year.
Up to 10,000 investors, many of them members of the Presbyterian Church in the North, were affected by a run on the PMS last year.
Large numbers of savers withdrew their deposits when it became clear the PMS would not be covered by a British government scheme, which guaranteed deposits of up £50,000 in high street banks.
With its funds severely depleted the PMS froze the accounts meaning many savers lost access to their life savings.
The Accountancy and Actuarial Board is now to investigate the key issue of the PMS' alleged unregulated financial activities.
The auditors include a number of individual accountants and the accountancy firm, Moore Stephens.
The firm welcomed the inquiry which they said was 'routine'.
