AUDITORS were not told of any potential problems in the Renewable Heat Incentive scheme, the inquiry into the botched project has heard.
Elaine Dolan, the chief auditor in the then Department of Enterprise, Trade and Investment (Deti), which was in charge of RHI, said she would have expected staff to raise potential risks to their managers.
However, she later told the inquiry she accepted responsibility for failing to spot issues in the scheme.
She said that as head of the internal audit, the buck stopped with her.
Panel member Dame Una O'Brien thanked her for accepting responsibility for auditing failures and added that such an acknowledgement was heard "too infrequently so far in this inquiry".
"I appreciate that it takes a lot given the nature of your work for you to have come and said that and thank you for being so frank with the inquiry," she said.
An audit in 2014, carried out by an external accountancy firm, failed to pick up any issues with RHI.
Ms Dolan said because Deti had retained the "quality control function" for its work, she was ultimately responsible.
The auditor who conducted the review accepted assurances from officials in Deti's energy division that the Office of Gas and Electricity Markets (OFGEM), which was administering the scheme, was responsible for it.
Ms Dolan said auditors had been given "the expectation that there were limited controls and monitoring arrangements that the department should have in place".
A subsequent audit of the scheme in 2016 found several problems - some of them coming from the fact there was no formal project management arrangement.
Ms Dolan said she agreed with the findings of the 2016 report.
She also told the inquiry allegations of fraud by concerned businesswoman Janette O'Hagan should have been referred to Deti's internal auditors.
Mrs O'Hagan contacted departmental officials several times to highlight alleged abuses of the scheme. But she said her claims were not taken seriously.
Ms Dolan said the allegations should have been referred to her team and would have prompted an investigation.
