Recommendations to prevent the repeat of a financial scandal which collapsed Northern Ireland's power-sharing executive have still not been fully implemented four years after they were made, a report has found.
The political fallout from the Renewable Heat Incentive scandal saw Sinn Féin withdraw from Stormont for three years from 2017.
The deeply flawed green energy scheme had been poorly designed.
The way it was established meant that people could turn a profit by running wood pellet boilers for long periods.
It was meant to divert people from fossil fuels to a renewable form of heat, but it became known as "burn to earn".
Subsequent reforms meant a huge overspend, which would have had to have been met from Stormont's public finances, was avoided.
But it left boiler owners with drastically reduced subsidy payments for expensive equipment which they had invested in on the strength of a government guarantee.
Former DUP leader Arlene Foster had been the minister in charge of the economy department when the scheme was designed.
Political rancour over the handling of the crisis led Sinn Féin to withdraw from coalition government.
An expensive public inquiry ensued which lifted the lid on the sometimes dysfunctional way that Stormont's mandatory coalition worked.
It made 42 recommendations. So far, 26 have been implemented.
The Northern Ireland Audit Office (NIAO), which was charged with overseeing compliance with the inquiry's recommendations, has said progress has been slow.
It said that in a number of areas the planned actions would not address the inquiry's findings and in respect of two recommendations, things had got worse.
Of particular concern to the NIAO is the issue of record keeping, which was a major talking point at the public inquiry.
Evidence was heard of a lack of proper record keeping, sometimes deliberate, to thwart Freedom of Information requests about decision making.
The NIAO said it was still having difficulty getting "timely access to adequate records" as part of its review.
Read the report in full here
Head of the NIAO Dorinnia Carville said the lack of progress was concerning.
She said: "The inquiry's findings demonstrated the significant learning and improvement that was needed from the NI Civil Service to rebuild public confidence.
"Four years on, a significant number of recommendations have yet to be fully implemented and, in our assessment, several are unlikely to be properly addressed by the actions currently planned."
