BEIJING (REUTERS) - It is not appropriate for Canadian pop star Justin Bieber to visit China because of his bad behaviour and he needs to improve his conduct to become a singer "truly loved" by the public, a Chinese state office has said.

His lifestyle overseas and his "words and actions" when he last performed in China had generated "public dissatisfaction", Beijing's Municipal Bureau of Culture said, without specifying what behaviour had caused offence.

Given efforts to "purify" the performing arts environment in China, "it was not appropriate to bring in artists with bad behaviour", the bureau said on its website, responding to a question from a fan asking why Bieber was not being allowed to tour.

"We hope Justin Bieber will continue to improve his behaviour as part of his growth and become a singer truly loved by the public," it said.

It is unclear whether the comments, which were carried on an official government website, constituted a ban or if the singer had sought to tour China.

His management company did not immediately respond to request for comment.

He performed in China in 2013 when media coverage centred on him stripping on stage in Beijing to reveal his bare torso, being carried up the steps of the Great Wall of China and riding a Segway, again shirtless, through the streets.

Bieber, 23, has become notorious for a string of indiscretions and scandals in recent years, shedding the clean-cut image he had when he burst onto the scene as a teenager.

He also posted a photo on social media showing him visiting Japan's controversial Yasukuni war shrine in 2014.

He removed the image but not before it had attracted 660,000 likes on Instagram and had been tweeted out to his more than 50 million followers on Twitter.

The Chinese media reported in January that Bieber was set to return this year, but no Chinese dates have been announced. He is due to perform in Tokyo, Hong Kong and Singapore in September and October, according to his website.

Several big-name musicians have been blocked from performing in China, including Lady Gaga, Bjork and Bon Jovi, who have all met or expressed support for the exiled Tibetan spiritual leader the Dalai Lama.

"Justin Bieber has won many big awards, he must have a lot of talent. Why have Chinese fans not been afforded the right to appreciate him?" asked He Wenrui, the fan who wrote to Beijing's bureau of culture.