Chinese submarine crew die after being stuck: UK intel report claims

• Report stated that everyone aboard died due to gas poisoning. 
• UK report, based on defence intel, is held at high classification.
• According to reports, China has denied any such incident.

As many as 55 Chinese sailors were claimed to have died after the nuclear submarine got stuck in a trap set for the United Kingdom sub-surface vessels, according to an intelligence report quoted by Daily Mail Tuesday.

The UK report read: "Intelligence reports that on the 21st of August, there was an onboard accident whilst carrying out a mission in the Yellow Sea."

The report stated that everyone aboard died due to the poisoning of the submarine oxygen crew underwater.

According to reports, China has denied any such incident.

It further read: "Incident happened at 08.12 local resulting in the death of 55 crew members: 22 officers, 7 officer cadets, 9 petty officers, 17 sailors. Dead include the captain Colonel Xue Yong-Peng. Our understanding is death is caused by hypoxia due to a system fault on the submarine. The submarine hit a chain and anchor obstacle used by the Chinese Navy to trap US and allied submarines."

"This resulted in systems failures that took six hours to repair and surface the vessel. The onboard oxygen system poisoned the crew after a catastrophic failure," added the report.

The UK report, which is based on defence intelligence, is held at a high classification.

A British submariner offered this explanation: "It is plausible that this occurred and I doubt the Chinese would have asked for international support for obvious reasons."

"If they were trapped on the net system and the submarine's batteries were running flat [plausible] then eventually the air purifiers and air treatment systems could have failed."

"Which would have reverted to secondary systems and subsequently and plausibly failed to maintain the air. Which led to asphyxia or poisoning."

"We have a kit which absorbs CO2 and generates oxygen in such a situation. It is probable that other nations do not have this kind of tech."

The similar kind of Chinese submarines are 351ft long and are armed with torpedoes.