Chinese Coast Guard boats chased and rammed Filipino scientists studying destroyed corals in a disputed area in the South China Sea.

Video shows Communist rigid hull inflatable boats approaching and colliding with the scientific expedition vessels during a coral health survey at the Escoda Shoal or Sabina Shoal on June 4.

A Philippine Coast Guard escort was heard saying: 'China Coast Guard, China Coast Guard, this is Philippine Coast Guard, we are conducting marine scientific research, please do not interfere.'

A Chinese sailor said through a megaphone: 'This is China Sea, this is China Sea, leave immediately.'

Despite the repeated collisions, the Filipino marine scientists said they were able to collect samples for their study.

Dr Jonathan Anticamara of the University of the Philippines Institute of Biology said there was extensive coral bleaching in the area.

He said in a June 7 press conference publicising the scientists' findings: 'I predict almost all of the corals in shallow waters of Escoda Shoal are now dead. That is an ecological disaster.'

Philippine authorities have previously blamed China and its alleged reclamation activities for the coral deaths in the area.

Expansionist China currently lays claim over almost the entire South China Sea, one of the world's busiest sea lanes. But a United Nations-backed tribunal in 2016 deemed its claims groundless.

The Communist rogue state - accused of genocide for its crimes against the Uyghur population - has been steadily increasing its influence in recent years through investment in developing countries.