HOHHOT, China (Reuters) - The wife of an ethnic Mongolian Chinese dissident who has been in jail for over a decade for separatism called on Sunday for the government to release him as a goodwill gesture ahead of the Olympics.

Hada was tried behind closed doors in China's northern region of Inner Mongolia in 1996 and jailed for 15 years for separatism, spying and his support for the Southern Mongolian Democratic Alliance, which sought greater rights for ethnic Mongolians.

Amnesty International considers Hada a prisoner of conscience and has expressed fears about his well-being.

"He's been in jail for 13 years. It's supposed to be a people's Olympics, a harmonious Olympics. Cannot they use this opportunity to let him out or grant an amnesty?" his wife Xinna told Reuters in an interview in the regional capital Hohhot.

"It hasn't happened. What's happened is the opposite. His situation has worsened," she added, over a traditional Mongolian breakfast of salty tea and sweetened, fried dough.

The Olympic torch reaches Inner Mongolia on Tuesday, and will pass through four of the region's cities, part of a journey whose international leg was marred by anti-Chinese protests following violent unrest in Tibet in March.

Next Thursday, the torch goes to the Inner Mongolian city of Chifeng, where Hada is jailed.

"It's highly ironic that the torch is going to Chifeng as there has been no improvement in Hada's situation," Xinna said.

"I wrote to President Hu to say I hoped that before the Olympics they could release my husband, but I got no response," she added, referring to Chinese leader Hu Jintao.

"I heard that China made a promise when it applied to host the Olympics that human rights would improve. But this has not happened, especially in the last few months."

Hada ran a Mongolian-language bookshop in Hohhot, along with Xinna. Inner Mongolia is supposed to have a high degree of autonomy, but like Tibet and Xinjiang in the far west, Beijing in practice keeps a tight rein on the region, fearing ethnic unrest in the country's strategic border areas.

China's treatment of its ethnic minorities has leapt into the limelight following the March unrest in Tibet and ahead of the Beijing Olympics, which open on Aug. 8.

Decades of migration by the dominant Han have made Chinese Mongolians a minority in their own land, officially comprising 20 percent of the almost 24 million population of Inner Mongolia.

Hada has repeatedly said that the charges against him were trumped up. China denies mistreating Hada and defends his sentence as being in line with Chinese law.

Xinna said she hoped the torch's arrival in Inner Mongolia would help to highlight her husband's plight, which has received less attention than other more well-known jailed Chinese dissidents such as AIDS activist Hu Jia.

"I want to take this opportunity to say that there has been no improvement in human rights in China," she said. "I hope international society pays more attention to Inner Mongolia and to my husband. They must put pressure on the government."

(For more stories visit our multimedia website "Road to Beijing" here; and see our blog at blogs.reuters.com/china)