Gonzalo Stampa (pictured center) specialized in international arbitration. The future of his legal career remains unclear following his conviction. Image Source: Royal European Academy of Doctors

The unanimous decision was announced on October 15. Spain’s highest court confirmed the original sentence issued by a Madrid criminal court in December 2023, which found Stampa guilty of contempt of court. The conviction carries a six-month prison term and a one-year ban on serving as an arbitrator.

The conviction carries a six-month prison term and a one-year ban on serving as an arbitrator.

With the Supreme Court's ruling, the case against Stampa and the Sulu lawsuit is now legally final in Spain. No further appeals are possible, marking a decisive end to a legal chapter that has drawn international scrutiny for its geopolitical implications.

Malaysia responded swiftly to the development. Datuk Seri Azalina Othman Said, Minister in the Prime Minister’s Department (Law and Institutional Reform), described the ruling as a clear reaffirmation of the rule of law and Malaysia's longstanding stance that the arbitration proceedings orchestrated by Stampa lacked legal validity.

“It demonstrates beyond doubt that the purported Sulu arbitration was the product of the unlawful and criminal conduct of a rogue arbitrator and vindicates the Government of Malaysia’s consistent position that the so-called award obtained by the Sulu claimants is null and void,” Azalina stated.

“It demonstrates beyond doubt that the purported Sulu arbitration was the product of the unlawful and criminal conduct of a rogue arbitrator.”

The arbitration itself has been the subject of global attention. In 2019, claimants who say they are descendants of the Sultan of Sulu initiated proceedings against Malaysia for alleged breaches of a colonial-era agreement related to land rights in Sabah. Stampa was appointed as arbitrator by a Spanish court.

However, in 2021, the High Court of Justice in Madrid revoked his appointment, citing procedural issues in how Malaysia was notified of the case. The court explicitly ordered Stampa to halt all arbitral activity.

Despite this directive, Stampa transferred the arbitration to Paris, where he ultimately issued a controversial award in 2022 ordering Malaysia to pay the claimants nearly $15billion. Spanish courts deemed this a direct violation of the judiciary’s authority, framing it as deliberate disobedience rather than a procedural oversight.

What pressures and calculations drove Stampa to proceed in open defiance of Spanish court orders remains unclear. His legal arguments—centered on the independence of international arbitration—were rejected at every level of Spain’s judicial system. The Supreme Court concluded that he knowingly ignored a valid and enforceable court order, attempting to sidestep judicial review by relocating the proceedings.

What pressures and calculations drove Stampa to proceed in open defiance of Spanish court orders remains unclear.

Despite this questionable conduct, at the time of publication, the Ilustre Colegio de la Abogacía de Madrid (ICAM) still list Gonzalo Stampa as a practicing attorney. While his one-year ban applies specifically to his role as arbitrator, ICAM has not yet announced any disciplinary action. However, the association has the authority to initiate its own review independent of the court’s ruling, which could potentially affect his broader legal practice.

In any case, observers note that it is unlikely that Stampa will serve his prison sentence over a first-time non-violent offense. Nonetheless, his actions have escalated tensions between Malaysia, Sulu, and the Philippines. Meanwhile, the broader dispute he enabled remains unresolved, as the Sulu claimants and their legal and financial backers continue to press their case on the international stage.