RHI behaviour was 'unacceptable'

Corrupt or malicious activity by ministers and special advisers was not the cause of what went wrong with Northern Ireland's failed energy scheme.

But the inquiry chair identified some instances where behaviour was "unacceptable".

Sir Patrick Coughlin said: "The vast majority of what went wrong was due to the accumulation and compounding of errors and omissions over time and a failure of attention of all those involved, in their differing roles to identify the existence, significance or implications of those errors and omissions."