Beijing - A 71-year-old Chinese journalist appealed Tuesday against her seven year jail sentence for "leaking state secrets", a conviction condemned by free speech advocates worldwide.
Dozens of police officers blocked access to the Beijing high court where Gao Yu appeared for an hour-long hearing.
The session was "closed" to outsiders, Gao's lawyer Mo Shaoping told AFP, adding he did not expect the guilty verdict to be overturned.
The septuagenarian has suffered from heart problems during her detention, but seemed "reasonably healthy", Mo said.
Named one of the International Press Institute's 50 "world press heroes" in 2000, Gao has been a consistent critic of the ruling Communist party's authoritarian policies.
A court ruled in April that Gao leaked a 2013 directive by the Communist party named "Document number 9" to a Hong Kong media outlet.
The document warned of the "dangers" of multiparty democracy, independent media, "universal" definitions of human rights and criticism of the party's historical record, according to copies widely circulated online.
The hearing comes as China's President Xi Jinping oversees a crackdown on dissent which has seen hundreds of lawyers, activists and academics detained in recent years, with dozens jailed.
China's already close controls on the media have been further tightened, reporters say.
France-based Reporters Without Borders ranked China 176th out of 180 countries in its 2015 Press Freedom Index.
State security prevented journalists and around a dozen foreign diplomats from standing near the court, telling them it was "not appropriate".
Gao's jailing was condemned by human rights groups and free speech advocates, while Washington called for her "immediate" release and the EU demanded Beijing "review" her trial.
A consistent advocate for democracy and free speech, Gao was imprisoned following the government crackdown on student protests in Tiananmen Square in 1989.
Her political writings saw her jailed for six years in the 1990s, also on a charge of "leaking state secrets".
She was detained again in the lead-up to the Tiananmen crackdown's 25th anniversary last year.