BEIJING (AP) _ The wife of a jailed Chinese dissident has asked President Clinton and the United Nations to help persuade Chinese authorities to free her sick husband for medical treatment.

Activist Liu Nianchun, 49, has been denied treatment for intestinal problems, swollen lymph nodes and other ailments, said his wife Chu Hailan in a letter sent to Clinton and the United Nations, the Human Rights in China group said Wednesday.

Chu had earlier asked Clinton to hand an appeal to President Jiang Zemin during his visit to the United States this fall, but there was no indication whether that request had reached either leader.

Liu was moved in secret to Beijing this fall from the Shuanghe labor camp in the northeastern province of Heilongjiang, according to the human rights group.

It said Liu was no longer able to eat or speak because of a tumor in his jaw and ulcers in his mouth.

Liu also suffers from growths in his colon and rectum, high blood pressure and rectal bleeding, conditions that prison doctors say require surgery, Chu said. Labor camp officials have refused to pay for the treatment and have insisted that Liu is receiving adequate care.

``My husband, Liu Nianchun, is seriously ill and cannot get treatment. His life is in danger. I send this special appeal to you to help secure medical care for him,'' Chu wrote, according to a copy of the letter supplied by Human Rights in China.

Petitions by Chu to Chinese leaders have been rejected or gone unanswered.

Liu is one of China's most prominent dissidents. He spent three years in prison in the early 1980s. He was picked up again in May 1995, during a sweep of dissidents before the anniversary of the June 4, 1989, military assault on pro-democracy demonstrators in Beijing.

He was never told why he was detained, and was held for a year before being sent to Shuanghe. Chinese police can send detainees directly to labor camps without going to court.