According to the news reported by the UK's "The Times" and "Dail Mail" newspapers based on the "secret" coded report allegedly leaked by British intelligence, the "Type 093" class nuclear submarine of the Chinese People's Liberation Army (PLA) Navy with the "093-417" starboard number was caught in an underwater obstacle called "anchor and chain" off the coast of Shandong province in northern China on August 21.
In the intelligence report, it was claimed that the submarine, which was caught in the trap "set by China for US and allied submarines", could not surface for 6 hours, and that the 55-member crew of 22 officers, 7 student officers, 9 petty officers and 17 privates, including the captain of the submarine, Colonel Shüe Yong-Pıng, died of oxygen deprivation due to the depletion of the batteries and the failure of the oxygen systems.
Speaking to the Dail Mail newspaper, a British submariner commented that China probably did not ask for international support for rescue when the incident occurred, saying:
"If they were caught in a net trap, it is likely that the submarine's batteries were depleted and then the air purification and regulation systems failed. In this case, the secondary systems would kick in, but they would not be able to supply enough air to breathe for long, leading to oxygen deficiency or poisoning."
Stating that the British navy has kits that convert carbon dioxide into oxygen for such situations, the sailor said that the same technology "may not be available" in other countries.
China has not yet confirmed the incident
China has not yet confirmed the incident, while the British Royal Navy declined to comment to the newspapers.
At the time of the incident, rumors spread on social media in China that a nuclear submarine had crashed near the Yellow Sea or in the Taiwan Strait.
Taiwan's Ministry of Defense reported on August 22 that "intelligence and monitoring devices have not detected a submarine accident in the region."
Chinese Defense Ministry Spokesperson Vu Chien also denied the rumors in a statement on August 31.
The nuclear-powered Type 093 submarines, also called "Shang-class", first joined the Chinese navy in 2006.
Six of the 107-meter-long and 6-ton submarines are still in service.