Mr Liu has been a political activist for more than two decades
Chinese police have recommended that prosecutors formally charge top dissident Liu Xiaobo with inciting subversion, his lawyer has said.
Mr Liu has been detained for a year without charge.
Mr Liu was detained on 8 December 2008 after co-authoring Charter 08, a manifesto urging political reform.
The likely charge of "inciting subversion to state power" is routinely used against anyone criticising the Chinese Communist Party.
"The public security organs feel the [prosecutors] should charge him and have recommended that they do so," Mr Shang said after seeing a copy of the recommendation.
"It is two-fold. One part relates to Charter 08 while the other relates to articles of his posted on the internet after 2005," Mr Shang said.
"This marks the end of the investigation phase and the beginning of the prosecution phase," he said.
Mr Liu is a writer and former university professor who has spent much of his time since being a leader in the 1989 Tiananmen Square democracy protests either in prison or under various forms of house arrest or close monitoring.
The Chinese government keeps a tight lid on protest and dissent
He has continued to write and publish his writings on the internet, calling for democratic pluralism in China.
Charter 08 is a petition first circulated online last year that calls for human rights protection and the reform of China's one-party communist system.
"We hope that our fellow citizens who feel a similar sense of crisis, responsibility, and mission, whether they are inside the government or not, and regardless of their social status, will set aside small differences to embrace the broad goals of this citizens' movement," the Charter says.
It has been signed by more than 10,000 people, including leading intellectuals, writers and dissidents, according to Chinese Human Rights Defenders, a network of activists.
Since Mr Liu's arrest, Western governments, rights groups, scholars and a group of Nobel Prize winners have called for his release.
His wife, Liu Xia, and a range of rights groups last week renewed those calls as the anniversary of his detention approached.
Liu Xia says she has not seen or spoken to her husband since March when police arranged a short, supervised meeting for the couple in a Beijing hotel room.
She said she was "outraged" after reading the three-page investigator's report.
"This report alleges that his crime is very serious and I expect they will try to jail him for 10 years or more," she said.