Below is an article published by the bbc.co.uk

The lyrics of the song are not exactly subtle: "The occupation and denial of freedom of Tibetans/This is torture without trace."

Another sounds a note of defiance: "Courageous patriotic martyrs/Have sacrificed their lives for Tibet/It pains my heart thinking of them/And the tears fall from my eyes."

Defiant the words may be, but they appear to have cost their writer his freedom.

The singer, Tashi Dhondup, was arrested in China at the end of last year, and in January he was sentenced to 15 months hard labour.

But his real crime may have been simply that he was so popular.

His CDs were passed among Tibetans, individual songs shared over the internet and by mobile phone.

"Tashi Dhondup reflected the trauma that Tibetans were feeling," said Dechen Pemba, a London-based blogger.

"The police came to his home and his wife was begging with the police officers - they're a young couple with a newly-born baby. But he was arrested and taken away."

Tashi Dhondup was not alone. Prominent Tibetan environmentalist Karma Samdrup was jailed last week for 15 years.

And according to a report by the International Campaign for Tibet, more than 50 writers, poets and musicians have been rounded up over the past few months.

Many have received tough sentences and, according to the campaign's spokeswoman Kate Saunders, many were people not usually regarded as dissidents.

"They're being... taken from their homes in the middle of the night," she said.

"These are individuals who are politically moderate, often secular, and yet the Chinese authorities are seeking to silence them."

It is still not clear exactly what motivated the crackdown.

Certainly, the last two years have seen a flowering of overtly-critical Tibetan songs, poems and other artistic outpourings.

They date from the protests that broke out in the spring of 2008, which saw violent confrontations between indigenous Tibetans and the ethnic Han Chinese who have been resettled there over the past few decades.

But despite clear challenges to Beijing's authority, Robbie Barnett, director of Columbia University's Modern Tibetan Studies programme, said the Chinese government itself may not be behind the arrests and prison sentences.

He believes that over-zealous local officials were the more likely instigators: "Local officials make their own minds up about who they're going to crack down on.

"They don't care about international responses. They may have an interest in being much more heavy-handed," he said.

Another writer who has been on the receiving end of this treatment is Shogdung - he was arrested in April and campaigners have not heard from him since.

Shogdung's case is particularly pointed, as he had previously been seen as loyal to the Chinese government - he had criticised Tibet's version of Buddhism - and had said the Tibetan people needed to sort out their own problems.

But in the wake of the 2008 battles, Shogdung had become increasingly critical of Beijing and this year published an unauthorised book The Line Between Sky and Earth.

It contained a scathing denunciation of Chinese rule: "My flesh is petrified, my bones hurt. They have made everyone helpless and desperate. In daytime, they run like jackals.

"At night, they sneak in like bandits.... we have been beaten, seized, arrested, condemned, sentenced, massacred. They have made us unable or afraid to move, to speak, to think. Everything and everyone has become inert because of fear."

One of the last people to meet Shogdung was the French journalist Ursula Gauthier, who interviewed him just two weeks before his arrest.

"He was clear he was heading for trouble," she said.

"But I'm not really sure he'll cope very well with detention. Although he looks very strong, I think he's more the fragile type."

The Chinese Embassy in London has refused to comment on Shogdung's case, or on the arrest and detention of any other Tibetans.

A spokesman said there was nobody available to discuss the matter.