Wisma Putra acknowledged there were reports of naval vessels loitering near an offshore oil rig within the Malaysian EEZ but said the matter fell outside its purview.

“We are unable to comment on the accuracy (of the reports) or specifics regarding the movements of military vessels as these matters fall under operational security and defence authorities,” it said in a statement.

The ministry said it would continue engaging diplomatically with the relevant countries in the region and defend Malaysia’s sovereignty and interests in the South China Sea.

China has claimed a vast stretch of the South China Sea under its controversial “nine-dash line” extending into Malaysian waters off Sabah and Sarawak.

The statement came in the wake of a report by Defence Security Asia, which quoted maritime observer Ray Powell as saying three China coast guard ships were found in Malaysia’s EEZ on Sept 3 near an oil rig operated by Petronas in the Kasawari gas field, which is estimated to be worth billions of ringgit.

Authorities in Sabah and Sarawak have previously complained that China coast guard vessels have encroached into Malaysian waters and harassed fishermen.

Last week’s report follows the leak of a classified diplomatic note from China to the Malaysian embassy in Beijing demanding that Malaysia immediately cease activities in an oil-rich area off Sarawak waters.

Malaysia does not recognise China’s 2023 standard map, which showed portions of Malaysian waters near Sabah and Sarawak as belonging to the republic.

Prime Minister Anwar Ibrahim previously said Malaysia would not halt its oil and gas exploration in the South China Sea despite Beijing’s claims.