Gao Yu, one of China's most prominent journalists, was sentenced to jail on April 17, 2015, on state secrets charges. Here, she is seen attending the opening of a photo exhibition by Liu Xa, wife of Nobel Laureate Liu Xiaobo, in Hong Kong, on June 9, 2012. Reuters/Bobby Yip

SHANGHAI -- A Chinese court has reduced the jail sentence given to veteran journalist Gao Yu from seven years to five years, following an appeal hearing. The move, which is rare in China’s Communist Party-controlled legal system, follows international pressure for the release of Gao, who was accused of leaking state secrets to international media. However, the court still upheld her guilty verdict, and human rights groups continued to call for the release of the 71-year-old, who suffers from heart problems and high blood pressure, on medical grounds.

“Gao Yu's slight sentence reduction is a sign that pressure works,” said Maya Wang, a Hong Kong-based researcher for Human Rights Watch, in a statement. “Now foreign governments should press for her to be released on medical parole.”

William Nee, a China Researcher at Amnesty International, said that while the verdict was a “light improvement”, Gao should not have been detained in the first place, and “should be released.” Gao’s lawyer Mo Shaoping told the New York Times he would apply to the court to allow her to serve the rest of her sentence outside prison on medical grounds.

Gao’s jailing in April was seen as a sign of tightening controls on society and freedom of speech under the leadership of China’s Communist Party Secretary General and President Xi Jinping. Full details of the charges against her were not officially revealed, but her family and lawyers say the journalist was accused of leaking an internal Communist Party document known as Document Number 9. The 2013 document called on the party to stamp out foreign ideological influences, particularly concepts such as universal values, Western style democracy, civil society and Western concepts of freedom of press.

After her arrest, Gao appeared on Chinese television and confessed to leaking secrets. However, during her trial last year she retracted the confession, which her son and lawyer have said she made under duress after threats from the authorities to take action against her son. The Chinese-American publisher to whom she is said to have leaked the document has denied that Gao was the source.

Gao, who worked for a liberal Chinese economic journal in the 1980s, was first jailed in 1989 for 15 months following the Tiananmen protests. In 1993 she was again jailed on state secrets charges after writing articles for Hong Kong media, and spent six years in prison. After her release in 1999 she was banned from contributing to Chinese media, but continued working as a columnist for the Chinese-language service of German broadcaster Deutsche Welle, as well as for websites in Hong Kong and the U.S. Deutsche Welle Director General Peter Limbourg recently described her sentencing as a “disgrace.”

No reason was initially made public for the reduction in Gao’s sentence. Observers said the reduction of the sentence was unusual, particularly since state secret charges tend to be deployed with the specific intention to “silence critics, dissenters, journalists and party foes,” as Nicholas Bequelin, regional director for East Asia at Amnesty International, put it at the time of Gao’s jailing. Some analysts have speculated that the reduction could imply weaknesses in the case against Gao.

Nevertheless, human rights groups say the Chinese government has stepped up its pressure on freedom of speech and civil society in recent months. As well as detaining a number of civil rights lawyers, and drawing up tough new regulations regarding the Internet and non-governmental organizations, the authorities have continued to target Chinese journalists: In the summer, they arrested a veteran reporter from financial magazine Caijing, who had reported that the authorities were considering ending their intervention to prop up the country’s slumping stock market. They have also recently introduced new media ethics committees, which experts say will put more pressure on press freedom, and have tightened rules for communist party members and academics, again targeting foreign ideas.

Amnesty’s William Nee said earlier this year that Document No. 9, which Gao Yu was accused of leaking, had in fact, become a “blueprint” for an “assault on human rights” by China’s leadership, in what he called “one of the worst crackdowns against rights activists in more than a decade."