The continuing validity of the foreign arrest warrant is a precondition for extradition

In judgment no. 32946/2026, the Italian Court of Cassation annulled a decision authorising extradition to Mexico in a case which had become procedurally rather complicated on the Mexican side.

The requested person was a Mexican national, resident in Spain, sought by Mexico for prosecution in connection with five arrest warrants issued by a judge in the State of Michoacán. The warrants concerned alleged fraud offences committed between 2020 and 2023.

On 12 May 2026, the Palermo Court of Appeal held that the conditions for extradition were satisfied.

By that stage, however, the defence had already placed before the Italian court a substantial amount of material concerning proceedings brought in Mexico against the measures underlying the extradition request.

Beginning in November 2025, the requested person had instituted a number of amparo proceedings before the courts of Michoacán. According to the documentation produced by the defence, provisional suspension orders had been issued in relation to three of the five arrest warrants and the corresponding extradition measures. The defence later maintained that definitive suspensions had also been granted.

The position was further complicated by conflicting information apparently coming from different branches of the Mexican authorities. Documents produced in December 2025 indicated that, in the amparo proceedings, the Mexican Prosecutor General’s Office had stated in relation to some of the measures that no provisional arrest warrant or extradition request existed. At the same time, the extradition procedure in Italy was continuing.

The Palermo Court of Appeal forwarded some of the defence material through the Italian Ministry of Justice seeking clarification. The response received from the Mexican Ministry of Foreign Affairs in December 2025 did not, however, explain the legal effect of the amparo proceedings and, more in general, the persistent validity of the domestic arrest warrants. It merely confirmed Mexico's “persistent interest” in obtaining extradition.

Subsequent developments further complicated the scenario. The defence produced additional material in April 2026 asserting that definitive suspension of the extradition measures had been ordered in relation to three warrants. Meanwhile, a Mexican court set aside an earlier decision declaring one of the amparo applications inadmissible and sent the matter back for examination. By the time the case reached the Court of Cassation, aspects of the Mexican proceedings therefore remained sub judice.

Against this background, the Cassation identified a series of connected problems concerning the authenticity of the documentation, the continuing enforceability of the foreign titles and the adequacy of the supplementary information obtained from Mexico. These problems warranted the quashing of the first-instance judgment and remittal before the Court of Appeal of Palermo for a fresh examination.

1. The authenticated arrest warrants

Article 7(2)(a) of the Italy–Mexico Extradition Treaty provides that a request for extradition for prosecution must be accompanied by an authenticated copy of the arrest warrant issued by the competent authority of the requesting State.

The documentation transmitted to Italy in the case reproduced the contents of the five warrants and indicated that the original paper documents would subsequently be sent. The authenticated copies themselves, however, were not in the case file.

Although the issue concerning the absence of authenticated copies had not been specifically raised before the Court of Appeal and was expressly relied upon only in the appeal to the Court of Cassation, the Supreme Court nevertheless examined that ground of complaint and considered the issue well founded.

That conclusion is easier to understand when the authentication issue is read together with the dispute over enforceability. The defence had already argued before the Court of Appeal that the warrants may have been suspended through the Mexican amparo proceedings. Once the continuing effectiveness of the warrants was in question, having an authenticated copy of the precise measures underlying the request was no longer merely a matter of form, but of substance.

The requested court was entitled to know which judicial measures were supporting the extradition request and whether those same measures remained executable.

The Cassation therefore required the Court of Appeal on remand to obtain authenticated copies of each of the five arrest warrants.

2. The warrants must still be enforceable when extradition is decided

The second and more substantial issue concerned the consequences of the Mexican amparo proceedings.

The Palermo Court of Appeal had not examined in detail whether the provisional or allegedly definitive suspensions affected the enforceability of the arrest warrants or the extradition request. Instead, it relied principally on the communication from the Mexican authorities confirming their continuing interest in obtaining extradition.

For the Cassation, this did not answer the question concerning the validity of the arrest warrant.

A State may continue to want a person extradited even though a domestic judicial decision has meanwhile affected the enforceability of the measure on which the request is based. It follows that the point is not whether Mexico continued to pursue extradition, but whether the five arrest warrants and the extradition request remained legally effective and executable under Mexican law at the time the Italian court ruled.

The Cassation did not itself determine the legal effects that Mexican law attaches to the various amparo measures, nor did it suggest that the mere pendency of amparo proceedings automatically precludes extradition. Those questions fall outside the remit of the court of last instance and required further factual and legal assessment. The case was therefore remitted to the Court of Appeal for renewed examination.

3. A statement of “persistent interest” was not enough

This leads us to one of the most useful aspects of the judgment.

The Italian authorities had, in fact, sought information from Mexico on the continuing validity of the arrest warrants and the extradition request.

The Mexican Ministry of Foreign Affairs failed to answer on that specific point, merely confirming its persistent interest in securing extradition.

The Cassation rejected the possibility of filling that gap by inference. The Supreme Court held that, where the defence has produced concrete judicial material suggesting that the underlying title may have been suspended or otherwise deprived of enforceability, a general reassurance from the requesting State is not enough.

The requested court must, therefore, obtain supplementary information specifically directed at resolving that issue. Notably, the Court of Appeal is required to obtain authenticated copies of the five arrest warrants and confirmation of their current enforceability. The Mexican authorities shall also clarify whether the extradition request itself remained effective, what had happened in the various amparo proceedings, whether suspension orders had been made, and, if so, what consequences those orders produced under Mexican law for both the warrants and the extradition procedure.

Seen in this way, the three issues identified by the Supreme Court are closely related: (i) the requirement to obtain authenticated arrest warrants identifies with certainty the judicial measures on which surrender is sought; (ii) the requirement of continuing enforceability establishes whether those measures can still lawfully support extradition; (iii) the duty to obtain supplementary information provides the means by which the requested court resolves any genuine uncertainty on that question.

4. Detention conditions in Mexico

The judgment also annulled the decision on a separate ground concerning detention conditions.

The defence had produced material concerning overcrowding and prison conditions in Mexico. Here too, the Cassation considered that the information relied upon by the Court of Appeal did not adequately respond to the specific risk alleged.

Where objective and updated material raises a real question as to the treatment to which the requested person may be exposed, the court must obtain sufficiently specific information concerning the institution in which that person will actually be detained. Where assurances are necessary, they must be specific, binding and capable of verification.

Although formally separate, this part of the judgment reflects much the same concern as the first issue on enforceability of the arrest warrant. General assurances cannot be considered sufficient where the defence has raised a concrete and individualised issue.