A lawyer has demanded Attorney-General Idrus Harun clear the air surrounding the questions raised over the US$14.92 billion (RM62.6 billion) final award by a Spanish arbitrator to the Sulu Sultanate's purported descendants.

In a statement today, Mohamed Haniff Khatri Abdulla said Idrus should respond to the lawyers representing the Sulu claimants who had refuted his statement issued on Feb 28.

"Through two shocking reports, the claimants' lawyers firmly said that at least two parts of the contents of Idrus's statement were false concerning the current position of the arbitration proceeding and the final award," he said.

Citing a Free Malaysia Today report yesterday, Haniff said the claimant's lawyer, Elisabeth Mason, insisted Malaysia had formally recognised her clients as the rightful heirs of the Sulu Sultanate for years.

Mason drew the conclusion based on the correspondence between former attorney-general Tommy Thomas and her colleague Paul Cohen in 2019. She said Idrus stating the "identities (of the claimants) are doubtful" was deeply misleading.

Haniff also noted that Idrus should have responded to Cohen, who accused Malaysia of twisting the facts on the arbitration.

Lawyer Mohamed Haniff Khatri Abdulla

Earlier today, Malaysiakini quoted Cohen as calling Malaysia a "rogue" nation unwilling to abide by its duties and responsibility as a signatory of the New York Convention.

"What the lawyer said about the descendants of the Sulu Sultanate presents not only a serious conflict with Idrus' statement but also challenges the dignity of the governance of Malaysia in the eyes of the world.

"Therefore, it is important for Idrus, as the attorney-general of Malaysia, to provide an immediate response and explanation to these serious allegations, not only for the understanding of Malaysians but also the world," he said.

While noting several proceedings related to the arbitration were still ongoing and pending disposal in Spanish and French courts, Haniff said it does not prevent or violate any legal principles for Idrus to respond and explain the matter.

"This is because the principle of sub judice does not apply in the international laws," he said, adding that the country's dignity may be impacted if Idrus fails to clear the air.

The Sulu descendants were awarded the arbitral amount following their claim that Malaysia breached the terms of an 1878 agreement.

The colonial-era 'treaty' was signed between then Sulu ruler Sultan Jamal al Alam, German-born adventurer Baron von Overbeck, and British businessperson Alfred Dent of Dent & Overbeck Company.

Malaysia was alleged to have violated the agreement in 2013 when it stopped making the RM5,300 annual payments to the Sulu sultan's heirs via the Philippine administration following the 2013 intrusion into Lahad Datu, Sabah, by an armed group from the southern Philippines.

The militants claimed to be linked to the Sulu sultanate.