Xuriyanggang, the hottest Chinese grassroots duo, was prohibited from singing their signature song by its composer, which caused a public debate on copyright in China.

Wang Xu, 44, and Liu Gang, 29, two migrant workers in Beijing, moved tens of millions of people with the song "In The Spring" in the China Central Television (CCTV) Spring Festival Gala, one of China'most-watched television events.

However, people will not enjoy it anymore since Chinese rock star Wang Feng, original singer and composer of the song, has banned them from presenting it in future.

"The reason why I allowed them to sing my song at the beginning was to help them, but I have to stop it after finding out my kindness was used," said Wang Feng.

Wang said on his blog Friday that his company had suggested Xuriyanggang many times to sing their own song before the Spring Festival Gala but they still kept using his work in all kinds of shows and activities.

Friday night, Xuriyanggang posted their apologies to Wang Feng on their microblog and admitted they knew little about the amusement circles.

"No matter what, we both owe a debt of gratitude to Teacher Wang Feng," said Liu Gang on their microblog. "We understand and respect Teacher Wang Feng's decision. We appreciate his help and encouragement to us in the past and feel sorry for all the troubles," said Wang Xu.

Last year, Xuriyanggang was invited as guest performers to Wang Feng's concert in Shanghai, which made them more popular.

According to Wang Rong, temporary assistant of Wang Xu, the appearance fee of Xuriyanggang had rise up to 50,000 yuan (7885 dollars) after their performance in the Spring Festival Gala.

Wang Feng's act also stirred an online storm in China. Some netizens consider him as narrow-minded and selfish, while others thought he was just protecting his rights.

"I like both Wang Feng and Xuriyanggang. This is a win-win situation because it both protects Wang's great efforts and let Xuriyanggang know they should have their own song," said Zhuidix on Sina Microblogging.

"This controversy reminded us the importance of copyright in music industry. Obviously, music writers care more about their rights when the industry is not so good nowadays," said Liu Ping, Deputy Director General of Music Copyright Society of China.

The song is under the protection of China's Copyright Law. As the copyright owner, Wang Feng has the right to do so, said Liu Ping.

In the semi-final of Star Road, a talent show sponsored by CCTV, presented Saturday night, Xuriyanggang still sang this song and won with it.

"I wish you can have your "summer," your "autumn" and your "winter," not just In The Spring," said Li Liqun, one of the judges in the show, implying they should not always perform the same song.

The two migrant workers became stars after singing the tearjerker song during an evening drinking session in a 6-square-meter rented room.

A friend recorded the performance on a cellphone and uploaded it on the Internet. The online comments following the video described it as the "cleanest," as they were unanimously positive.

The song, "In the Spring" was recognized by many as a portrait of a migrant's life. Wang Xu, one of the duo, said the song reflected their real life in the substrata of society.

"We will still be down-to-earth in future. One day, we will have our own song," said Wang Xu.