El-Khouri [2025]: Extradition Offences and the Rule of Double Criminality

Last Wednesday, the Supreme Court (“UKSC”) handed down its judgment in El-Khouri v Government of the United States of America [2025] UKSC 3, providing important clarification on the concept of an ‘extradition offence’ and the operation of the ‘double criminality’ rule.

Mr. El-Khouri – a dual UK/Lebanese national living in the UK – had been requested by the US in relation to his alleged making of payments to a ‘middleman’ to obtain confidential information about major M&A deals involving listed US companies, and then using this information to make trades in contracts for difference for profit (“CFDs”). Overturning the decision of both lower courts, the UKSC quashed the order for Mr. El-Khouri’s extradition and ordered his discharge.

‘Extradition offences’ – the statutory framework

For a person to be extradited, the conduct for which they are sought must amount to an ‘extradition offence’ under the Extradition Act 2003 (“EA 2003”). Central to this is the rule of ‘double criminality’, which in essence requires that, when ‘transposed’ into a UK-context, the relevant conduct must amount to a UK offence. This process of ‘transposing’ the relevant conduct to the UK to examine whether it amounts to an offence is sometimes referred to as the ‘transposition exercise’.

ss.137-138 EA 2003 contain the conditions in which conduct will constitute an ‘extradition offence’ in Part 2 cases, with the relevant provision in Mr. El-Khouri’s case being s.137. s.137 contains alternative sets of conditions, which provide for slightly different ‘double criminality’ tests depending on whether the conduct took place ‘in’ or ‘outside’ the requesting territory. The UKSC considered in particular the conditions in s.137(3) and (4):

‘(3) The conditions in this subsection are that –

(a) the conduct occurs in the category 2 territory;

(b) the conduct would constitute an offence under the law of the relevant part of the United Kingdom punishable with imprisonment or another form of detention for a term of 12 months or a greater punishment if it occurred in that part of the United Kingdom;

(c) the conduct is so punishable under the law of the category 2 territory.

(4) The conditions in this subsection are that –

(a) the conduct occurs outside the category 2 territory;

(b) in corresponding circumstances equivalent conduct would constitute an extra-territorial offence under the law of the relevant part of the United Kingdom punishable with imprisonment or another form of detention for a term of 12 months or a greater punishment;

(c) the conduct is so punishable under the law of the category 2 territory’.

Decision of the UKSC

The UKSC’s judgment is notable in three regards: (1) it clarifies what constitutes ‘conduct’ occurring ‘in’ or ‘outside’ a requesting state; (2) it makes explicit the correct approaches to the ‘transposition exercise’ required by the rule of double criminality; and (3) it overturns the decision of the Court of Appeal in R v Rogers [2014] EWCA Crim 1680, which had held that money laundering offences had an extra-territorial reach.

s.137(3)(a) – Did the conduct occur ‘in’ the US?

In the Administrative Court, the US relied exclusively on s.137(3) to establish that the alleged conduct constituted an ‘extradition offence’. Under s.137(3)(a), the conduct must have occurred ‘in’ the US. However, none of the principal protagonists were based in the US, nor were the CFDs bought or traded in the US – in a literal sense, the vast majority of the alleged conduct occurred in the UK.

To satisfy s.137(3)(a), the US relied on an aged House of Lords decision, Cando Armas [2005] UKHL 67, in which Lord Hope observed, obiter, that conduct occurs ‘in’ the requesting state even if the person is not physically present in the territory, provided that the effects of their conduct are intentionally felt there. The US submitted that the offending conduct occurred ‘in’ the US because its effects were felt on US markets: a submission accepted by both lower courts.

The UKSC rejected this approach, dismissing Lord Hope’s comments as ‘mistaken’ for three reasons:

1. The plain language of 137(3)(a) and s.137(4)(a) simply does not accord with such an expansive interpretation of ‘conduct’.
2. 137(3) and s.137(4) must be mutually exclusive, otherwise conduct would have to be capable of occurring simultaneously ‘in’ and ‘outside’ the requesting territory. Lord Hope’s approach is not compatible with this.
3. Lord Hope’s reasoning was based on the common law rules of criminal jurisdiction, which are irrelevant to the statutory scheme in the Extradition Act 2003.

Instead, the word ‘conduct’ is to be given its ‘ordinary meaning’, and s.137(3)(a) and (4)(a) are to be read as ‘concerned solely with where the physical acts alleged were done and not with where any effects of those acts (intentionally or otherwise) were felt’ [my emphasis]. On this approach, the conduct had plainly occurred ‘outside’ the US, and the appropriate provision was s.137(4), not s.137(3).

The transposition exercise – ‘mirroring’

The UKSC also provided clarification on the approach to be taken to the ‘transposition exercise’ required by the rule of double criminality.

Mr. El-Khouri argued that, under s.137(3)(b), when the court is conducting the transposition exercise the facts must be ‘mirrored’ so that any conduct which occurred outside of the requesting territory must also be treated as having occurred outside of the UK. Rejecting this, the UKSC made clear that s.137(3)(b) simply requires the court to assume that all conduct took place in the UK: no transposition in the opposite direction is required. In the present case, this meant no transposition was necessary because almost all the alleged acts in fact occurred in the UK.

In contrast, however, the UKSC stated that such a ‘mirroring’ exercise is required under s.137(4)(b). Unlike s.137(3)(b), the test of double criminality under s.137(4) includes the term ‘corresponding circumstances’, which requires transposition in both directions to ‘construct a mirror image of what actually occurred’.

As s.137(4) (not s.137(3)) was the correct provision to be used in El-Khouri, the UKSC applied this ‘mirroring’ approach and concluded that the mirrored conduct could not constitute any available extra-territorial offence in the UK. In doing so, the UKSC overruled the decision of R v Rogers [2014] EWCA Crim 1680, which held that the money laundering offences in ss.327-329 Proceeds of Crime Act 2002 had extra-territorial reach.

Conclusion

The UKSC’s judgment in El-Khouri [2025] provides necessary clarity on the concept of an ‘extradition offence’ under the Extradition Act 2003. While the jettisoning of the dicta in Cando Armas [2005] was apparently unexpected by the parties, who had not initially prepared submissions on this point, it is a welcome and sensible recalibration.

James Cox is a barrister at 2 Hare Court and accepts instructions across extradition law, crime, and professional discipline. For full details of his practice, click here.