The Badminton World Federation  has charged eight Olympic doubles players with "not using one's best efforts to win a match".

Four pairs of players - two from South Korea, one from China and one from Indonesia - could be disciplined.

Constant errors, including players serving into the net, were made.

All four pairs had already qualified for the last eight and have been accused of wanting to lose in an attempt to manipulate the draw.

The federation meets on Wednesday morning to discuss the case. As well as the "not using best efforts" charge, the players are also accused of "conducting oneself in a manner that is clearly abusive or detrimental to the sport". Options open include expulsion from London 2012.

Teams blamed the introduction of a round-robin stage rather than a straight knockout tournament as the catalyst. In the round-robin format, losing one game can lead to an easier match-up in the next round.

In the first women's doubles match at Wembley Arena on Tuesday night, fans jeered China's Yu Yang and Wang Xiaoli and South Koreans Jung Kyung-eun and Kim Ha-na .

The longest rally in the first game lasted four shots, with match referee Thorsten Berg coming onto the court at one point to warn the players.

South Korea won the Group A match, which lasted 23 minutes, 21-14 21-11.

Both pairs were already through to the quarter-finals, with the winners to face China's Tian Quing and Zhao Yunlei. The two Chinese pairings can now only meet in the final.

Korea's coach Sung Han-kook said: "The Chinese started this. They did it first. It's a complicated thing with the draws. They didn't want to meet each other in the semi-final, they don't want that to happen.

"They (BWF) should do something about that."

But Yu said the Chinese decided to preserve energy ahead of the knockout stages.

She said: "Actually these opponents really were strong. This is the first time we've played them and tomorrow it's the knockout rounds, so we've already qualified and we wanted to have more energy for the knockout rounds."

A later match between South Korean third seeds Ha Jung-Eun and Kim Min-Jung and Indonesian pair Meiliana Juahari and Greysia Polii was played out in a similar atmosphere.

Referee Berg returned to court and brandished the black card, signalling disqualification, but it was rescinded and the match resumed when the Indonesians protested.

Both pairs had also already qualified for the knockout stages, with the winners of Group C to play Yu and Wang and the Korean pairs to face each other if Ha and Kim lost.

The Koreans won 18-21 21-14 21-12 and did not comment before leaving the court, but Polii said: "I don't know what happened. If that's the game, we have to accept all the things.

"Either they want to trust us - we play bad or we play good. Our control is only to play as good as we can."

Gail Emms, a badminton Olympic silver medallist for Great Britain in 2004, who was at the event for BBC Sport, said: "I'm furious. It is very embarrassing for our sport.

"This is the Olympic Games. If badminton wants to save face they should disqualify the two pairs and reinstate the pairs that came third in the group.

"This is something that is not acceptable. The crowd paid good money to watch two matches."

The International Olympic Committee said it had "every confidence" in the badminton federation to "deal with the issue appropriately and take any necessary measures".

China's Olympic sports delegation has begun an investigation into the matches, state media reported. The country's Olympic Committee opposed any behaviour 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.

Source: www.bbc.co.uk