A newly-placed Borr Drilling rig has found itself at the centre of an international naval standoff over rights to the disputed South China Sea.

The standoff marks China's furthest reach southward to date in asserting its offshore claims, some 44 nautical miles off Malaysia's Sarawak state.

It also shows Malaysia's navy taking active measures to respond to what analysts called "harassment" by China in waters of the Malaysian exclusive economic zone.