Philippine Coast Guard (PCG) spokesperson on West Philippine Sea concerns, Rear Admiral Jay Tarriela, on Sunday dismissed China’s use of a 1990 letter by former Philippine ambassador Bienvenido A. Tan Jr. to a German radio hobbyist as proof that the Philippines conceded sovereignty over Scarborough Shoal. He described it as "misleading" and a "distortion of historical records" in his post on X.

Tarriela said the document being circulated by the People's Republic of China was not an official waiver of sovereignty.

“The PRC’s attempt to present this 1990 letter as proof of Philippine concession over Scarborough Shoal (Bajo de Masinloc) is misleading at best and a deliberate distortion at worst,” Tarriela said. He added that the correspondence merely noted that the shoal lies outside the colonial boundaries defined in the Treaty of Paris of 1898 but affirmed that it falls within the Philippines’ 200-nautical-mile exclusive economic zone.

Scarborough Shoal—known locally as Bajo de Masinloc and by China as Huangyan Dao—has been a major flashpoint between Manila and Beijing since the 2012 Scarborough Shoal standoff, when Chinese maritime forces took control of the area following a confrontation with Philippine vessels.

The shoal lies about 124 nautical miles (around 230 kilometers) off the coast of Zambales in the West Philippine Sea.

Tarriela said that under international law, an ambassador does not have the authority to waive or abandon a country’s territorial claims. He cited retired Supreme Court Associate Justice Antonio Carpio, who has previously said only statements from a head of state or foreign minister can bind a nation on issues of sovereignty.

Tarriela said the letter was merely “casual correspondence to a private individual” and cannot be treated as a binding admission by the Philippine government. He also said reliance on the document ignores the ruling of the Permanent Court of Arbitration in the 2016 South China Sea Arbitration, which affirmed that the shoal lies within the Philippines’ exclusive economic zone. It had ruled that China’s sweeping historic rights claims in the South China Sea have no legal basis under the United Nations Convention on the Law of the Sea.

China first publicized the supposed "concession" letter years ago, but its renewed circulation appears aimed at supporting Beijing’s territorial claims in the disputed waters, Tarriela said.

“The fact remains: China has not once exercised sovereignty over Bajo de Masinloc. The PRC claim is bogus and has no credible historical basis,” Tarriela pointed out.