Hospital had conducted regular checkups on Liu Xiaobo

The prison where Liu Xiaobo had stayed said on Friday that it had conducted regular health checks on Liu and set up a health file for him.

Records provided by the Jinzhou prison show that Liu had a history of hepatitis B before being admitted into the prison. Since the sentence, the prison provided him with an annual physical examination, and doctors made health visits to him twice a month.

Since 2012, Liu received annual hepatitis and tumor screening in addition to the routine health check, but no physical abnormalities were found, according to the prison.

On May 31 this year, a health check found suspicious conditions in his abdominal cavity, so the authorities quickly arranged for him to leave the prison for further medical checks, the prison said.

Liu was sentenced to 11 years in jail in December 2009 for inciting subversion of state power. He was released on medical parole upon diagnosis of liver cancer in June.

He died of multiple organ failure due to liver cancer on Thursday at the age of 61.

The First Hospital of China Medical University, where Liu received medical treatment, had done its best to save his life, his main doctor Liu Yunpeng said late on Thursday.

Well-known experts from China as well as Germany and the United States were also invited for joint consultations, said the doctor, but medical efforts still failed.

"US and German experts spoke highly of the hospital's work, believing the patient had received quality treatment. They held that hospitals in their own countries could not have done a better job," Liu said.

He also said Liu Xiaobo's type of liver cancer was very hard to diagnose at an early stage, and that it developed very quickly in the late stage.