Chinese Olympic delegation has begun an investigation into allegations two badminton players “deliberately lost” their match, state media says.

Doubles players Yu Yang and Wang Xiaoli are among eight players charged by the Badminton World Federation (BWF) with “not using one’s best efforts to win”.

Four players from South Korea and two from Indonesia have also been charged.

China’s Olympic Committee opposed any behavior which violated “sporting spirit and morality”, a spokesman said.

Further action could be taken based on the results of the investigation, the spokesman said in a report published by Xinhua news agency.

Reports have suggested both pairs wanted to lose to secure an easier draw.

Chinese Olympic delegation has begun an investigation into allegations two badminton players "deliberately lost" their match

The match between the top-seeded Chinese duo and South Koreans Jung Kyung-Eun and Kim Ha-Na came under scrutiny after the longest rally in their game lasted four shots.

Match referee Thorsten Berg came on court at one point to warn the players, who also appeared to make deliberate errors.

Both pairs were already through to the quarter-finals.

The Chinese duo lost, meaning – Xinhua noted – that if both Chinese pairs continue to do well, they will not meet until the final.

Yu Yang said after the match that the performance was about saving strength.

“We’ve already qualified, so why would we waste energy? It’s not necessary to go out hard again when the knockout rounds are tomorrow.”

A subsequent match between South Korean third seeds Ha Jung-Eun and Kim Min-Jung and Indonesian pair Meiliana Juahari and Greysia Polii also came under scrutiny, with both teams apparently keen to lose – and so avoid the Chinese in the next round.

A statement from the BWF confirmed that all four pairs would face charges of “not using one’s best efforts to win a match” and “conducting oneself in a manner that is clearly abusive or detrimental to the sport”.

It is not clear what kind of penalties they could face. They are due to play in the quarter-finals later on Wednesday.

Australian coach Lasse Bundgaard said the group format of the tournament was to blame.

“If you can win a medal by losing, but not by winning, that’s not a good situation to be put in,” the Associated Press news agency quoted him as saying.

But a commentary piece carried by Xinhua was more reflective. The players’ actions did not “break any rules”, it said, but such behavior damaged “sportsmanship and ethics”.

“It is purely an act just for getting gold, with absolutely no respect to the spectators. You will be widely criticized even if you win the gold medal in the end,” the commentary read.

“Is it more important for us to ensure a gold-winning opportunity, or to protect China’s image and to spread the Olympic spirit?”

The row provoked heated debate on Sina Weibo – one of China’s Twitter equivalents. Moderators put up a page dividing comments into support and criticism of the players – and 70% of commentators backed the players.

One user in Beijing said: “It all depends on the result! Once the result is right, the way you achieve it doesn’t really matter.”

But another from Foshan in southern Guangdong said: “Passive competition, no matter what, goes against the Olympic spirit. All you want to achieve by doing this is to secure both gold and silver.”