A Chinese Navy ship 'stalked' a Philippine government vessel as it sailed through disputed waters on Friday.

The BRP Francisco Dagohoy of the Philippine Bureau of Fisheries and Aquatic Resources (BFAR) had just finished an aid mission and was travelling near the Pag-asa Island off Palawan province on June 16 when the gray Chinese military ship with bow number 549 appeared on the horizon.

The Filipino crew said they were surprised by the ship's approach as its Automatic Identification System had been turned off, rendering it invisible on the radar.

The military vessel then sped up and closed the gap, maintaining a distance of one nautical mile from the much slower Philippine ship.

Crew onboard the BRP Francisco Dagohoy said the Chinese Navy vessel did not issue a radio challenge and merely tailed them without further incident.

Speaking to local media, BRP Francisco Dagohoy Commanding Officer Lieutenant Commander Mark Adrias said: 'We will submit a formal report with the National Task Force for the West Philippine Sea.

'We saw that it was a gray ship. It was from the Chinese Navy. So far, we didn't see them doing any aggressive maneuvers from the Chinese ship.'

Pag-asa Island is the largest in the Kalayaan group of islands sitting in disputed waters between the Philippines and China.

Under the UN Convention on the Law of the Sea (UNCLOS) of which China and the Philippines are signatories, the area is located within the Philippine Exclusive Economic Zone.

However, China has repeatedly ignored international rules, claiming ownership over nearly the entire South China Sea through its 'nine-dash line' claim, which has been invalidated by the UN Permanent Court of Arbitration in The Hague in 2016.