In October 1950, the People's Liberation Army of China quashed resistance in the Tibetan town of Chamdo, leading to the Chinese occupation of the country which remains to this day. Over the past 60 years, a committed campaign has sought to highlight the alleged Chinese persecution and oppression of the Tibetan people as part of centuries old wrangling over the north Himalayan territory.

Against this backdrop, filmmaker Dirk Simon set out to follow the struggle for Tibet in his new documentary feature, When the Dragon Swallowed the Sun. After growing up in East Germany before the Berlin Wall fell, freedom became a subject very close to Simon's heart. This gave him the courage to investigate Tibet under Chinese rule from the perspective of its younger generations.

China's claims over Tibet goes back centuries, though the country managed to achieve independence in 1913, a status it has held for 37 years. Justifying the latest occupation, China says that it has liberated Tibet from an exploitative feudal system. Another perspective is that this 'liberation' has resulted in the deaths of 1.2 million Tibetans.

"In a society where freedom of speech doesn't exist and even the internet is censored, it will always be difficult to obtain evidence [of the persecution]," according to Simon. "But corruption has become a big problem in China and Chinese police officials sometimes sell video footage proving the violence beyond any doubt. Former Tibetan political prisoners that have escaped to India after their release also attest to how they were treated or what they saw while being held in a prison camp."

Documenting such delicate issues proved a unique challenge for Simon. Apart from the interviews, most footage in his film was shot "guerrilla style" without permission, and he often had to be "extremely careful" not to reveal the production's true nature. "While filming in Beijing and Tibet, we had a few close encounters with the Chinese military and agents in plain clothes," he reveals. "Besides our regular HD cameras, we always had a smaller HD camera hidden. Thanks to a great crew that always stood by me, we pushed the envelope more than once and the footage is truly amazing."

While trying to condense 700 hours of footage into just two hours achieving a sense of balance presented Simon with further challenges. He tried to give an honest view of the issue while avoiding cliché, but a true representation of all views proved to be unattainable.

"Gaining access to key Chinese officials was impossible, filming in China was fraught with obstacles and obtaining the trust of Tibetan groups took years," he says. "Ironically, even those who were supposed to benefit most from this film were sometimes the most difficult with whom to collaborate. It took seven years to make this film, in no small part to all these challenges. I was committed to portraying the reality facing the Tibetan freedom movement and I strongly believe we achieved that."

In part, the documentary deals with growing frustration among Tibet's younger generations about the lack of progress under the Dalai Lama's Middle Way Policy of non-violent action. As the 73-year-old Nobel laureate prepares to step aside, Tibet faces fresh challenges in achieving its liberation aims.

"Even the Dalai Lama has officially acknowledged that his approach has failed," according to Simon. "The voices within the Tibetan movement that doubted the Dalai Lama's strategy over the past twenty years have more leverage now. But I am not sure if you can really speak of a shift yet. That still has to happen."

During the 2008 Beijing Games, the event's usual pomp was punctured by protests calling for China's withdrawal from Tibet. However, this PR shot in the arm for the campaign proved fleeting, as attention quickly shifted to another cause de jour. Attuned to the pull of celebrity, Simon secured participation from actor and committed Buddhist Richard Gere for the film, while its soundtrack features music from Radiohead's Thom Yorke, composer Philip Glass and singer Damien Rice, along with UNKLE, Eric Clapton and Björk. However, Simon was careful to only work with people who could add creative value.

"We tried to reach beyond the typical audience for this kind of film by creating emotional access to the story through engaging cinematography and a powerful soundtrack," explains Simon. "So we reached out to some of our favourite artists who we felt could help us accomplish these ambitious goals. After we explained our concept and they saw some material, Philip, Damien and Thom all answered the call. The sum of creative contribution makes this film truly unique. Additionally, the attention given to such high-profile artists helps tremendously to spread the message."

As the film readies for its world premiere, Simon is expecting that there will be some "opposition" from China to its content. Equally, given the country's record for heavy censorship, it's unclear whether anyone in China will actually get to watch it. Simon said that the film's website has recently received thousands of hits from within China, but this could result in it being banned by the government. However, he adds: "The film also reveals a few painful truths about the Tibetan freedom movement and it is unclear how all the Tibetan support groups will respond. In my opinion, the film shows a very honest perspective, but one that not everyone may be able to appreciate."

Screening information: U.K. screenings have not yet been confirmed, but there are plans for shows in summer 2010. See throughanexilelens.org or whenthedragon.com for more.