BEIJING--A Tibetan filmmaker jailed in China for making a film about the Olympics and Tibet has escaped from China and arrived in the United States, according to an activist group which campaigned for his release.

Dhondup Wangchen was jailed for six years in late 2009 in the western province of Qinghai after he made a documentary in which ordinary Tibetans praised the Dalai Lama and complained about how their culture had been trampled upon.

The film, "Leaving Fear Behind," features a series of interviews with Tibetans who talk about how they still love their exiled spiritual leader and thought the 2008 Beijing Olympics would do little to improve their lives.

The film was shown in secret to a small group of foreign reporters in Beijing during the 2008 Olympics.

In a statement late on Wednesday Beijing time, the group Filming for Tibet said Dhondup Wangchen had arrived in San Francisco that same day.

"After many years, this is the first time I'm enjoying the feeling of safety and freedom," the group quoted him as saying.

"I would like to thank everyone who made it possible for me to hold my wife and children in my arms again. However, I also feel the pain of having left behind my country, Tibet."

He had been released from prison in June 2014 in Qinghai provincial capital Xining but remained under tight surveillance with his movements and communications monitored, the group said.

"Dhondup Wangchen was able to successfully evade the authorities and flee from his home area in Tibet and then the People's Republic of China altogether," it added, without giving details.

China's Foreign Ministry did not immediately respond to a request for comment. The Xining police declined comment and the Qinghai provincial government did not answer telephone calls.

Qinghai, which borders the Tibet Autonomous Region, is home to a large ethnic Tibetan population and considered by many Tibetans as part of greater Tibet. It is also the birthplace of exiled Tibetan spiritual leader the Dalai Lama.

There have been sporadic protests against Chinese rule in Tibetan parts of China for the past few years, most seriously in 2008 ahead of the Beijing Olympics.