Three weeks after Christmas, a package wrapped in plastic appeared on John Penn de Ngong's bed.

Unwrapping the parcel, the South Sudanese poet-cum-activist found a jawbone, a bullet and a death threat signed by a group that called itself the Committee for the Operation to Restore Patriotism in South Sudan - CORPSS.

The handwritten note warned him to stop writing or he would get the same "gift" as his friend Diing Chan Awuol, an outspoken columnist who was shot in the face and killed at his home in the capital Juba in early December.

"We thought it was (the jaw) of a human being that night, but later the national security said it was the jawbone of a dog, and a bullet," Ngong said, speaking by telephone from a secret location abroad.

In July 2011, South Sudan was carved out of Sudan, the culmination of a 2005 peace deal that ended decades of brutal civil war between southern insurgents and the central government in Khartoum.

A year and half on, the ecstasy of long-awaited independence has given way to the punishing task of finally translating the old rebel slogans of freedom and democracy into a blueprint for running a secure and stable state.

There are signs South Sudan is already sliding toward censorship of its nascent media. Dissenting voices like Ngong accuse the young government of clamping down on the very freedoms its leaders spent decades fighting for in the bush.

Before he was killed, Ngong's friend Awuol - better known by his pen name Isaiah Abraham - had published a piece that called on the government to foster better ties with its old foe Sudan and refrain from supporting rebel groups across the border.

"They see us as a threat," Ngong said. "It is very disheartening for us, war survivors, to achieve our independence from the government we thought was our oppressor only to find ourselves on the run again."

HIT LIST

Despite noisy declarations about finding Awuol's killers, the government turned down assistance of a detective from the United States Federal Bureau of Investigation.

The government says it has made several arrests, but none of the suspects has been brought before court and Awuol's family says the investigation has stalled.

After his friend's death, Ngong started assembling a book of Awuol's essays and his own barbed poetry.

He claims this, and his other writings, put him on a hit-list of government critics.

A misspelled threat sent from a CORPSS email address ordered him to "stop your unpatrotic compaigns againist your own country, we can get you! Understand?"

Ngong isn't alone in his concerns for the direction of the young country, whose relatively peaceful birth was heavily supported by Western powers.

This year, South Sudan slipped 13 places to 124 out of 179 countries on the world press freedom index compiled by media watchdog Reporters Without Borders.

Political commentator Zechariah Manyok Biar, who wrote about the need to track down Awuol's killers, fled the country in December after a policeman told him he had overheard two men talk about killing him.

He says he traced two cars that were following him; one belonged to the presidential protection unit, the other to a policeman.

"They thought they would restore patriotism by killing people," Biar said by telephone from an undisclosed location outside the country.

In January, two U.N. human rights officers investigating Biar's case were arrested and interrogated by South Sudan's security service for several hours.

Government spokesman Barnaba Marial Benjamin said the investigation into Awuol's assassination was ongoing and rejected Biar and Ngong's harassment claims.

"It is mud-slinging on the government. It is not true. If it is true, bring it to the police," Benjamin said.

ANIMAL FARM

South Sudan's minority leader of parliament, Onyoti Adigo Nyikwac, accuses the ruling Sudan People's Liberation Movement (SPLM) - which controls more than 90 percent of the legislature's seats - of abandoning its stated principles of "unity, equality and progress" once it gained power.

"The SPLM has become like Animal Farm, where all animals are equal but some are more equal than others," Nyikwac told Reuters, referring to a George Orwell novel that parodied Soviet Russia.

Corruption has become a serious problem. Midway through last year a letter by President Salva Kiir was leaked to the press, in which the president asked some 75 ministers and officials to return $4 billion of stolen government money.

The government acknowledged the letter was genuine. Government spokesman Benjamin said at the time that more than half of the missing funds were from the country's so-called "durra" scandal, in which a large government purchase of sorghum was allegedly never distributed.

But despite the rise in threats and attacks against dissenting voices, including members of his own party, Nyikwac doesn't see the crackdown as a deliberate policy from top levels of government.

The problem, he says, is the confusion wrought by myriad security agencies operating with weak or often competing command structures and no law governing their work.

In the dingy reception area of National Security headquarters, staff sit transfixed by American wrestling on television.

Minister for National Security Oyay Deng Ajak acknowledged there were problems in the security sector but said he hopes to overcome these by the drafting of a National Security policy.

That may not be enough to reform forces that diplomats say operate above the law. Nominally, the directorate for internal security is part of the Ministry of National Security, but in reality it answers to the Presidency, said Jok Madut Jok, head of the Sudd Institute think tank.

"Nobody is held accountable. The disconnect between the policies and what (security organs) do is the main driving force behind the restriction of the press," he said.

Local journalists say state-sponsored intimidation and impunity are having a profound impact on the media landscape.

One local journalist, who asked to remain anonymous, said the climate of fear since Awuol's assassination has made most journalists "sing to the tune of national security."

BITTER PILL

Western donors have been exasperated by the crackdown and by the young country's decision to shut down its oil industry in a row with Sudan over pipeline fees more than a year ago.

Yet they have shown little appetite for cutting aid because of the risks to regional security were South Sudan to collapse.

One foreign diplomat said donors are likely to swallow the bitter pill of bailing out the government by pledging to pay salaries of teachers and health-workers at an upcoming donor meeting in Washington D.C., despite human rights abuses.

Tom Rhodes of the Committee to Protect Journalists said successful liberation movements like in Eritrea and Zimbabwe had failed to uphold freedom of expression in the past, but foreign governments and aid agencies were often willing to accept that.

"I rarely find instances where donors cut aid because of human rights abuses," he told Reuters by telephone.

That is unlikely to give much comfort to government critics and their families.

At a memorial service three months after Awoul's assassination, family members hung a banner demanding the government bring his killers to justice.

"Is this the South Sudan we fought for?" the banner read.

By Hereward Holland

Photo: Security forces leaving the scene of an operation at Juba Day Secondary School where live fire wounded two people and terrified pupils who had been protesting at a construction site adjoining the school grounds, 31 October 2012 (Radio Tamazuj).