73. The final two errors again occurred on separate warrants. In the first case
there was a failure to suspend a postal check pending its deletion from a
warrant. In the second case it was the result of an official failing to sign the
modification authorisation to a warrant.
74. Twelve errors were reported by GCHQ, of which four are highlighted
below. In the first case the CSP noticed that the Schedule to a warrant that was
sent to them contained a wrong number. The CSP informed GCHQ
immediately and no targeting or interception of the number took place.
Modification deletion instruments to remove the number were subsequently
signed. Checks are always made to ascertain subscriber details for numbers
being proposed for targeting but on this occasion the error was not spotted. In
light of this, GCHQ has reviewed its internal working arrangements.
75. In another case a modification instrument was signed adding an additional
number to a warrant Schedule held by a CSP authorising the interception of
mobile telephone numbers. However, staff in GCHQ noticed that the
modification to add an additional number to the CSP’s Schedule was, in fact,
the first of that CSP’s number on this warrant. The modification should,
therefore, have constituted a modification to insert a new Schedule (in respect
of the CSP) and should have been accompanied by the Schedule addressed to
that CSP, together with a requirement for assistance notice. As soon as this
error was noticed, steps were taken to prevent the number in question from
being intercepted. One call had been intercepted but had not been listened to:
this data was immediately destroyed. Corrected paperwork was subsequently
submitted. It appears that this error arose out of simple oversight when drawing
up the modification instruments. GCHQ has revisited its procedures for
ensuring that appropriate checks are made in this aspect of the submission
process.
76. The third case concerned modification instruments to add numbers to two
of GCHQ’s existing warrants. The modifications were signed and distributed to
the two relevant CSPs. On receipt of the instruments both CSPs informed
GCHQ that the instruments they each had received contained telephone
numbers of the other CSP. The CSPs did not take the actions necessary to
enable interception to be carried out. GCHQ took the appropriate action to
rectify the errors. Further investigations by GCHQ revealed that numbers
owned by the two CSPs had been incorrectly assigned to modification
instruments within GCHQ’s warrant database and that manual checks had
failed to spot these errors. GCHQ are in the process of amending the warrant
database to prevent a recurrence of such errors in the future.
77. The fourth case concerned the intercept from a targeted number which
had been dual-routed to both GCHQ and SIS. SIS expressed concern to
GCHQ that the target was no longer using the particular mobile telephone
number under interception. Investigations within GCHQ confirmed this fact.
Interception was terminated at once. Modification deletion instruments were
submitted to delete the number from the warrant. Enquiries of the CSP
established that the target had cancelled his mobile telephone and, as is normal
practice, the CSP held the number in “storage” for four months before reallocating it to a new subscriber. A period of unlawful interception therefore
took place. There were, in total, 184 intercepts of this number: none were
looked at by GCHQ and none were transcribed. All have now been deleted.
GCHQ’s internal procedures have been reviewed and actions taken to prevent
a similar error arising again.
78. Two incidents were reported to me by the Northern Ireland Office. The
first concerned an error in the interception of a mobile telephone used for the
purposes of national security. Intelligence received indicated that the target
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