Accountants inspected 300 sites which were generating most heat after allegations of abuse in the renewable heat scheme.
Inquiry chair says he will investigate failings in the botched energy scheme "wherever accountability may lie".
A timeline of events relating to the Renewable Heat Incentive scandal which caused the collapse of Northern Ireland's government.
Arlene Foster and Jonathan Bell's accounts are contradictory - how can we find where the truth lies?
BBC News NI answers commonly asked questions about the Renewable Heat Incentive scandal.