Chinese fans are demanding an apology after official merchandise for the World Team Table Tennis Championships in London twice featured a wrong version of their nation’s flag.

Fans noticed that China’s flag on the commemorative merchandise – posters, T-shirts, hoodies – sold on the International Table Tennis Federation’s website had six stars instead of five.

They took to social media to lash out at the federation and Table Tennis England, host of last week’s championships, for showing disrespect to their country’s flag. They also demanded an apology.

In the wake of the backlash, the federation changed the flag on the merchandise – priced at between £35 and £67 – but without publicly acknowledging the mistake.

The revised version wasn’t accurate either, showing five yellow stars but in the wrong place, angering the fans further.

The Independent has reached out to the federation for comment.

The Chinese national flag is red with a large yellow star near its top-left corner and four smaller stars arranged in a semicircle to its right.

A widely shared post about the merchandise reportedly drew more than 10,000 comments and related discussions spread quickly.

“Do you have even the slightest respect for China and the athletes?” a Weibo post with 2,000 likes said.

“Which country has a six-star red flag?” another asked.

One user urged the Chinese Table Tennis Association to take action, saying: “What is the Chinese Table Tennis Association doing? If you want to make money from us, learn to show some respect first.”

“Why is there no media coverage and why is it trending on social media?” another fan asked. “This is an international organisation openly provoking the Chinese people. Where are the Chinese fans? Why are only a few people speaking out?”

This isn’t the first time that a major sporting event has shown a wrong flag for China.

At the 2016 Rio 2016 Summer Olympics, organisers repeatedly used a red flag with the four smaller stars in the wrong place during medal ceremonies involving Chinese athletes. The four smaller stars were printed parallel to each other instead of angled towards the large star in an arc.

Chinese officials lodged complaints, forcing Rio organisers to publicly apologise and replace the flags.