When China's women's volleyball team won their nation's 26th and final gold medal of the Rio Olympics, the celebrations were tinged with more than a little annoyance.The cause of the irritation was that somehow, once again, an incorrect version of the Chinese flag was hoisted high during the medal ceremony.Chinese fans took to social media to vent their anger. There was a resurgence in a hashtag which translates as "Rio Olympics Using Wrong Chinese National Flag"; which has been used more than eight million times on the Sina Weibo micro-blogging platform. This time most of those using it were asking variations of the same question: 'How could the Rio Olympics make the same mistake again?'.On the first day of the games, the incorrect flag was used during the medal ceremony of the women's 10m air rifle with China's Du Li and Yi Siling as silver and bronze medal winner respectively.

The errors in the flag were immediately pointed out and produced an apology from Mario Andrada, Communications Director for Rio 2016. New correct flags were swiftly ordered and were used for almost all of the remaining medal ceremonies in which China was involved. So there was considerable disbelief when the wrong design resurfaced right at the end of the Olympics.The Rio Olympic committee is reportedly investigating how this happened and is expected to tender an official apology to China.One Weibo user complained,: "Making such a mistake again is really absurd! Chinese people can't accept the apology from Rio Olympic Committee."

So what were the errors in the incorrect flag?

The proper Chinese flag features one big star surrounded with four smaller stars against a red background.

The larger yellow star represents the Communist Party of China, and the four smaller stars symbolise the solidarity of Chinese people of all social classes and ethnic groups under the leadership of the CPC. In the correct version the four smaller stars all point towards the big star.

When the wrong flags first appeared some media reports mistakenly claimed that they had been manufactured in China.But this was strongly denied by a spokesman for the firm that was blamed, Zhejiang Wuyi Jinyu Textile Co Ltd. A company spokesman said: "We are not responsible for the wrong Chinese national flags that are used at the Olympics ceremonies. The national flags we've manufactured are for the audiences.. Being Chinese, how can we get the Chinese national flags wrong?! "Later the Rio Olympic committee admitted that the offending Chinese flags were made in Brazil and promised to investigate.However, this has failed to pacify some Weibo users. "Rio Olympics is rubbish," wrote one user called Kepler. "Not only were the referees not fair, but also getting the Chinese national flags wrong again. Brazil has no qualification to hold and compete in the Olympics."Another commenting using the name Ghz joked, that there was at least one positive: "This Olympic ends. My big gain is that I finally know what the Chinese national flag looks like. Thanks Rio!"