ALMOST a year and a half after he was detained by police, the parents of Dr Kang Yuchun, one of 19 dissidents reportedly about to be put on trial for allegedly organising a counter-revolutionary group, have still not been formally notified of their son's arrest. The only information Kang's parents have received since their son's disappearance on May 6 last year is a note from the hospital where he worked saying the Public Security Bureau was ''handling'' his case. In what is being called a ''flagrant violation'' of China's criminal law, the family has not been told where Kang is being held or the reason for his arrest. Relatives have not been allowed to see him or send him letters, and have no information about his state of health. Friends of the family say that Kang's parents, both elderly farm workers who live in a small village an hour's drive from the centre of Beijing, are at a loss as to what to do. Kang's father has fallen ill because of worry over his son's disappearance and can no longer work. The friends say the family is experiencing great financial hardship. Kang, 29, who worked at the Anding Hospital in northern Beijing, was one of dozens of people rounded up in the capital last summer for suspected involvement in underground democracy groups. They have been held in detention for more than a year and it is understood that 16 of those arrested plus three alleged accomplices from Sichuan province will be tried in secret within the next month. The 19 are said to have been charged with organising a counter-revolutionary group and ''counter-revolutionary propaganda and incitement''. They could face from five years to life imprisonment if found guilty. While the families of many of those arrested have been notified, Kang's case stands out because of the almost complete lack of information provided to his family. The New York-based human rights group, Asia Watch, has reported Kang's case to the United Nations Committee on Disappearances. It is not known if the committee has approached the Chinese Government yet. Asia Watch spokesman Robin Munro said Kang's disappearance was a ''violation of all relevant international standards and China's own criminal law''. Asia Watch will pursue the case until the Chinese Government provides an explanation of its actions, the spokesman added. The Hong Kong Government has further extended the visa of exiled labour unionist Han Dongfang. Yesterday's extension was the third since Mr Han was expelled from China two months ago when he returned to the mainland after a stay in the United States. He was expelled and his passport was declared void by the Public Security Ministry, which claimed Mr Han had engaged in anti-government activities when he was abroad. Mr Han has filed a lawsuit alleging that the action by the ministry was illegal.