Troubled insurer RSA is to take legal advice on possible action related to Deloitte's audits of the group in the period before financial irregularities which emerged at its Irish arm resulted in a £200m 'black hole' in the accounts.

RSA's chief financial officer Richard Houghton told Reuters: 'The board has considered this matter. We will take appropriate external advice to see what our course of action might be.'

Houghton said that RSA's chairman Martin Scicluna who has been running the firm since chief executive Simon Lee resigned in December over the accounting scandal has excluded himself from board discussions on the matter because of his former role as a partner at Deloitte.

A review by PwC, which was published yesterday, found that the issues at the company's Irish operations were attributable to 'inappropriate collaboration' relating to claims irregularities among a small number of senior executives in Ireland, which undermined the effectiveness of the insurer's controls.

A Deloitte spokeswoman said: 'We have not seen the PwC report nor RSA's own review, and are not in a position to comment. Deloitte is committed to delivering the highest quality audit services.' KPMG succeeded Deloitte as auditor in May 2013.

RSA's Irish subsidiary (RSAII) is also being investigated by the Central Bank of Ireland over the shortfall and could face a large fine equal to 10% of its turnover in the prior year if the regulator finds cause for reprimand. This could add up to a potential £35.4m fine. Any executive found to have broken the rules could face a fine of up €1m (£830,000).

A spokesman for the Bank said: 'The Central Bank is continuing to examine the issues in relation to RSAII and will continue to liaise with RSAII and other stakeholders.'

The regulator added that its investigation is likely to take 'some months'.