Cash for ash scandal
The top ten news stories of 2016
The botched Renewable Heat Incentive (RHI) scheme, dubbed cash for ash, has dominated headlines this month.
The programme was intended to help businesses meet the cost of installing renewable energy technologies, such as wood pellet burners.
However, some firms were able to reap huge profits by needlessly burning fuel because there was no cap on the limit that could be claimed.
In February, the then Minister for Enterprise, Trade and Investment, Jonathan Bell, announced the closure of the scheme.
In December, First Minister Arlene Foster - who introduced the programme as Enterprise Minister - faced criticism after it was revealed the programme could cost the taxpayer £400m and a whistleblower had contacted her department warning the scheme was open to abuse.
Mr Bell claimed Mrs Foster's advisers attempted to remove her name from RHI documents. He also said two DUP advisers did not allow the scheme to be closed and that the First Minister demanded he keep it running. All concerned deny wrongdoing.
Mrs Foster has since survived a vote of no-confidence and said the Executive was working on reducing losses.