A China Coast Guard tagged as "The Monster'' because it is said to be the biggest vessel in the world is leaving the Philippines' exclusive economic zone but will be replaced by another ship, the Philippine Coast Guard (PCG)said Wednesday.

The huge Coast Guard ship, which has bow number CG 5901, has been in the Philippine exclusive economic zone since Saturday. Radio challenges were made by a Philippine Coast Guard BRP Cabra, even as a People's Liberation Army-Navy helicopter hovered close to it on Tuesday.

The big Chinese Coast Guard ship was last sighted 90 nautical miles offshore as it departed from the coastline of Zambales. It will be replaced by CCG-3103, which left Guangdong Province. It was heading directly to the previous location of ''The Monster'', the PCG said.

The PCG said CCG-3103 was sighted at 60 nautical miles from Pandaquit, Zambales.

''This indicates that CCG-3101 is likely serving as a replacement vessel for ''The Monster'' ship, thereby sustaining its illegal presence within the Philippines' Exclusive Economic Zone,'' the PCG said.

The Philippine government has voiced over the presence of the big ship. DMS