evidence would not adversely affect the fairness of the trial was correct and the way he exercised his
discretion could not be impugned.
As to the application of Code C of the Codes of Practice to the instant case, although it extended
beyond the treatment of those in detention, it was intended to protect suspects who were vulnerable
to abuse or pressure from police officers. The situation in the shop was quite different. The
appellants were not being questioned by the police officers acting as such. Conversation was on
equal terms. There could be no question of pressure or intimidation by the officers as persons
actually in authority or believed to be so. Therefore, the judge was correct in ruling that the Code
was not intended to apply in such a context.
Per curium: It would be wrong for police officers to use or adopt an undercover pose or disguise to
enable themselves to ask questions about an offence uninhibited by the requirements of the Code
and with the effect of circumventing it.
We submit that is exactly what has happened in this case. My Lord, if I can refer your Lordship to
page 267 in the reports. Your Lordship will see the final paragraph. It says; The first limb of Mr.
Thorntons first submission depends strongly on the speeches in R. v. Sang (1979) 69 Cr.App.R.
and deals with the question of entrapment.
However, the existence of a discretion in the judge to exclude legally admissible evidence, so as to
secure the fairness of the trial, was recognised as extending further than merely the exclusion of
evidence more prejudicial than probative,
and it refers to other cases.
Lord Diplock also pointed out that the only case brought to their Lordships attention in which an
appellate court had actually excluded evidence on the ground that it had been unfairly obtained by a
trick was R. v. Payne (1963) 47 Cr.App.R.
There was a defendant, charged with drunken driving, had been induced to undergo a medical
examination to see if he was ill on the understanding that the doctor would not test his fitness to
drive. However, the doctor gave evidence based on his examination that the defendant was unfit to
drive and Court of Criminal Appeal quashed the conviction.
and they said; This again, as it seems to me, said Lord Diplock, is analogous to unfairly inducing a
defendant to confess to an offence and the short judgement of the Court of Criminal Appeal is
clearly based upon the maxim nemo debet prodere se ipsum
The passage relied upon by Mr. Thornton where Lord Diplock said;
Nevertheless it has to be recognised that there is an unbroken series of dicta in judgements of
appellate courts to the effect that there is a judicial discretion to exclude admissible evidence which
has been obtained unfairly or by trickery or oppressively, although except in R. v. Payne there has
never been a case in which those courts have come across conduct so unfair, so tricky or so
oppressive as to justify them holding that the discretion ought to have been exercised in favour of
In every one of those cases to which your Lordships have been referred where such dicta appear,
the source from which the evidence sought to be excluded had been obtained has been the
defendant himself or (in some of the search cases) premises occupied by him; and the dicta can be