124
Investigatory Powers Commissioner ’s Annual Report 2019
18. Errors and breaches
Overview
18.1
Investigation of errors and breaches reported to us by the authorities we oversee is an
important part of our work. We may also discover potential errors during the course of
our inspections. These are then investigated by the authority concerned and formally
reported to us. We investigate all matters reported to consider the impact the error has
had on the human rights of any individual affected, and to consider whether the report
reveals any failings in the processes and safeguards in place at that authority. Our website
includes details about the type of errors we investigate and provides examples of the kind
of issues we see.
Notable errors reported in 2019
MI5 compliance error
18.2
Full details of the compliance error identified by MI5 and our investigation into their failure
to demonstrate adequate compliance processes across certain technology environments
is given in chapter 8. We are confident that MI5’s internal review of safeguards, initiated
following the realisation of the severity of the issue, and the potential for this to have
resulted in multiple errors in data handling, will identify any substantial vulnerabilities in
their data handling model and lead to the elimination of errors of this kind in the future.
Her Majesty’s Revenue and Customs (HMRC) covert human intelligence sources
(CHIS) error
18.3
HMRC reported an error in relation to its management of witnesses who assisted in
investigations and gave evidence in support of a small number of prosecutions. Over
the course of several years, those investigating officers who engaged with potential
witnesses failed to consider that many of these individuals were acting as CHIS and
required authorisation. The cause of the error originated from a misguided policy which
had, in turn, been misapplied by many officers involved in these operations. The public
authority undertook a comprehensive review of current and historic investigations
to identify the number of affected prosecutions. As the policy had been in force for
approximately 15 years, a significant number of investigations were involved. Importantly,
the number of cases where convictions had been obtained and such a witness was used
during the investigation who should have been the subject of a CHIS authorisation was
comparatively small; in single figures. It should be noted that the CPS has taken the view
that none of the convictions secured was unsafe and that HMRC has fully discharged its
disclosure obligations.
18.4
We have worked closely with HMRC, including conducting an interim inspection to focus
solely on the remedial measures which have been implemented to avoid recurrence. HMRC