By Jim Wolf

WASHINGTON, Oct 23 (Reuter) - The United States called on China on Wednesday to free immediately a Tibetan-born Fulbright scholar and said it knew of no basis for Chinese charges he was a spy funded by "some Americans."

The State Department said it had no information that Ngawang Choephel, who studied ethnomusicology at Middlebury College in Vermont in 1992-93, had been doing anything other than videotaping traditional dances when he was detained by Chinese authorities in September 1995.

"In the absence of any evidence that he has committed any crime, we urge the Chinese and the Tibetan Autonomous Region authorities to release Ngawang Choephel immediately," spokeswoman Julie Reside said.

The Chinese Embassy said in a letter to members of Congress made public on Tuesday that Ngawang had been detained on charges of spying for the exile government of the Dalai Lama, Tibet's spiritual and political leader, which is located in Dharamsala, India.

"We have learned that, funded by some Americans, Ngawang Choephel was sent by the Dalai Lama's 'government-in-exile' to Tibet, used the cover of so-called collecting Tibetan folk songs to gather sensitive intelligence and engaged in illegal separatist activities," embassy counsellor Shao Wenguang wrote.

Reside said the U.S. government was limited in what it could do for Ngawang, a stateless person who was travelling on an Indian identity certificate when he vanished in Shigatse, Tibet, on or about Sept. 15, 1995.

She said his selection as a Fulbright scholar under an international educational exchange programme funded by the U.S. Information Agency showed a high U.S. opinion of him but did not give the United States any extra consular powers to demand a meeting with him.

"Thousands of Americans have taken the time to write to express their concern," she said. "The U.S. government, based on its understanding of the matter, shares this concern."

In a letter to Representative Bernard Sanders, an independent from Vermont who was one of the moving forces behind a congressional petition on Ngawang's behalf, the embassy said that Ngawang was suspected of violating Article 4, Section 2(5), of the Chinese State Security Law, an espionage statute.

"The judicial department of the Tibetan Autonomous Region is handling his case according to law," Shao Wenguang wrote on behalf of Ambassador Li Daoyou in the Oct. 15 letter.

The International Campaign for Tibet, a Washington-based advocacy group, said Ngawang went to Tibet in the summer of 1995 to film a documentary about its cultural heritage. The Dalai Lama and others have accused Beijing of trying to dilute Tibetan culture by encouraging Chinese settlement.

China frequently accuses the Dalai Lama, leader of the more than 6 million Tibetan Buddhists and winner of the 1989 Nobel Peace Prize, of fomenting anti-Chinese uprisings in Tibet, which Chinese troops entered in large numbers in 1950.