Nguyễn Thị Ánh Viên worked under Huang Guohui ©Getty Images

Huang Guohui - who coached Vietnam’s swimming team at the Tokyo 2020 Olympic Games here - has died in quarantine after returning from the Japanese capital.

The Chinese coach, who was also known as Hoang Quoc Huy, died in a hotel in Hanoi while undergoing a 14-day isolation period along with the rest of the Vietnamese Olympic team.

The cause of his death has yet to be confirmed, but the VnExpress reports that authorities are suspecting suicide as they carry out an investigation.

"Coach Huang passed away on August 11," a statement from Vietnam’s Chef de Mission Trần Đức Phấn read.

"We are in isolation, so we don’t know the situation yet and we are waiting for the result of the police investigation."

Phấn also confirmed that Huang had been double vaccinated against COVID-19.

Nguyễn Huy Hoàng benefitted from his time working with Huang Guohui as he won gold at the 2018 Youth Olympics ©Getty Images
Nguyễn Huy Hoàng benefitted from his time working with Huang Guohui as he won gold at the 2018 Youth Olympics ©Getty Images

Huang started working with Vietnamese swimmers in 2003 before going to help them to achieve plenty of medal success at the Asian Games and the Southeast Asian (SEA) Games.

He coached Nguyễn Huy Hoàng and Nguyễn Thị Ánh Viên, although neither made it beyond the heats at the Olympics in Tokyo.

Under his tutelage, Huy Hoàng struck gold in the men’s 800 metres at the 2018 Youth Olympic Games in Buenos Aires.

Huy Hoàng also achieved five medals at the SEA Games, winning gold in the 1500m freestyle in 2017 before topping the podium in 400m freestyle and 1500m freestyle in 2019.

He also won 1500m freestyle silver and 800m freestyle bronze at the 2018 Asian Games in Jakarta and Palembang.