Neither did he know that he would face a possible death sentence, a fate that befell him a few months after April 22, 2005, the day he crossed the border.

The soft-spoken, bespectacled correspondent had gone to the city to meet a source, who was to hand to him a politically sensitive manuscript containing secret interviews with former Chinese premier and Communist Party chief Zhao Ziyang.

Instead, he was met by security agents who detained him.

It was a politically sensitive period, as Zhao, who had opposed the June 1989 Tiananmen crackdown and had been under house arrest since then, had died on Jan 17, 2005, at the age of 85.

But Mr Ching, now 58, the Chief China Correspondent of The Straits Times, had thought nothing of it.

As it later turned out, his arrest had nothing to do with the manuscript.

Until today, no one is sure of the real reason for his arrest, but he has been charged, tried and jailed for spying for monetary gain, charges which he has denied throughout his trial.

A top journalist who had broken many stories on China, he was to find himself enmeshed in the cross-strait rivalry between Beijing and Taipei. In the process, he would receive treatment that other journalists who had cut too close to the chase in the realm of Chinese politics had also faced - long periods of detention, quick, closed-door trials and terse explanations from the authorities who said little.

A day after he was nabbed, Mr Ching called his wife Mary Lau, now 56, to have his laptop sent across the border.

A few days later, on April 28, he called this newspaper from Beijing to inform his employers that he was helping in an investigation.

It was not until more than a month later on May 31 that the Chinese government made public his detention, accusing him of spying for foreign agencies and receiving payment for it.

By then, the Washington Post had broken the story of his detention, causing a sensation.

Days before that, Straits Times editor Han Fook Kwang had met Ms Lau in Hong Kong to try and find out what had actually happened and how to proceed with the matter.

Since hearing about Mr Ching's detention, 'we were quietly trying to find out more information, working through the Chinese Embassy in Singapore to secure his release', Mr Han said yesterday.

The newspaper had decided not to go public with the information 'for fear of jeopardising these efforts', he said, explaining why ST had not publicised the detention in April.

When the news broke, Mr Han met Ms Lau in Hong Kong again, en route from a conference in Seoul, this time with lawyers that the paper had engaged, to discuss how best to proceed.

Mr Ching, a former deputy editor of a pro-Beijing Hong Kong newspaper Wen Wei Po, joined The Straits Times in 1996 and had risen to become its Chief China Correspondent when he was detained. The post was left vacant in his absence, as the company kept him on its payroll.

Journalists from around the world also rallied to the support of one of their own, with 500,000 from more than 100 countries signing a petition calling on China to treat Mr Ching's case in an open, fair manner, consistent with the rule of law.

In Hong Kong, where he had lived for most of his life and was well liked by the journalistic fraternity for his soft avuncular ways and sharp analytical mind, people rallied to his side. Groups sprang up to fight for a fair trial and later an early release, including one organised by his old friend and lawyer David Hui, 52, called the Ching Cheong Incident Concern Group.

It was to be another two months before Mr Ching would be formally arrested and charged, in early August.

During that time, the Hong Kong media went to town with the case, speculating on the reasons for his detention.

He was not the first Hong Kong journalist to have been detained by the Chinese government, but the first since the former British colony's return to the Chinese fold in 1997 under the one country, two systems formula.

When the formal charges were finally made known, those who knew Mr Ching well found them hard to believe.

The official Xinhua news agency reported that the journalist had been charged with spying for Taiwan intelligence, the National Security Bureau of the island that China regards as a renegade province.

It said Mr Ching had gathered a great deal of information on China's political, economic and especially military affairs, some of it 'top secret' and 'confidential', and had passed this to the Taiwanese intelligence authorities, harming Chinese national security.

Friends and associates who knew Mr Ching to be a patriot supportive of reunification between China and Taiwan found it hard to believe that he would spy for the pro-independence administration of Taiwanese President Chen Shui-bian.

Hong Kong media mostly rose to his defence, except for pro-Beijing newspapers and magazines, which sided with the Chinese government's version of events.

The United States expressed its 'great concern' over the case, saying 'freedom of the press is a fundamental and internationally recognised right' and that it viewed 'any attempt to restrict this right with great concern'.

Hong Kong Chief Executive Donald Tsang promised that his government would do all it could to help Mr Ching, a Hong Konger.

Nevertheless, a one-day closed-door trial a year later in August 2006 found him guilty as charged.

Under China's laws, those found guilty of espionage face jail terms of three years or more, or even the death sentence.

For Mr Ching, the sentencing later handed down was five years behind bars.

He has maintained his innocence throughout, saying that any information that he had passed to the Taiwanese think-tank, Foundation on International and Cross-Strait Studies (FICS), deemed by the Chinese to be a front for espionage, was in the public domain.

Since his sentencing and failed appeal in November 2006, life proved a roller-coaster ride for Mr Ching and his family, as they worked to secure an early release.

Imprisoned at first in Beijing, he was moved to Guangzhou early last year at the request of his family, so that they could visit him often.

But then friends and relatives worried that because the Chinese government had agreed to the move, it meant that it would be harder to obtain an early release.

In the meantime, Mr Ching's family, friends and supporters worked hard to secure early parole on medical grounds as his health deteriorated, including petitioning Hong Kong and Chinese government officials.

At every occasion where they thought their chances were greatest, such as Chinese New Year, the anniversary of Hong Kong's return to China and even the inauguration of Mr Tsang as Chief Executive, they would put in their appeal.

Each time, there would be rumours of his impending release. But each time, there was only disappointment.

Just last month on the 1,000th day of Mr Ching's incarceration, said Mr Hui, his Ching Cheong Incident Concern Group had written to the authorities to ask for his release.

But he did not get his hopes too high, as the group had been rebuffed once too often.

So when he heard yesterday that Mr Ching was released - for real - he was surprised and elated.

'This is good news, especially at this particular moment, because it's the eve of the Chinese New Year, and this is when we Chinese have the family reunion,' he said.

'This is good for his family and for the people of Hong Kong.'

Legal analyst Ong Yew Kim of Hong Kong, however, was not surprised by the news.

He cited several possible reasons for the move, including the Chinese government's desire to maintain its standing with the world, given that the Olympics will be held in China this year.

Another factor could be that the Chinese government is in a positive mood, after pro-unification Kuomintang in Taiwan won last December's legislative elections, dealing the independence movement there a heavy blow. The mood in Hong Kong is also good with most people finally accepting China's plan for full democracy in 2017. Besides, the Chinese government has made building a 'harmonious society' its main focus.

'It is a fair decision to him, to The Straits Times, and it can win the hearts of the Hong Kong people,' said Mr Ong.

ST's Mr Han said: 'It's a great relief. I'm extremely happy for him and his wife Mary.'

He noted that it had been a trying period thus far because the paper had had no access to Mr Ching and was therefore unable to obtain his side of the story, except through the lawyers.

He added that the paper would be discussing his future plans with him, in due course.

The Hong Kong Journalists Association said it regretted that Mr Ching 'was innocently held in jail for three years'.

Still, his release 'takes away the bad feelings we have about the situation in China. His case showed that there is a lot of ambiguity of the laws surrounding (journalism) in China,' said association official Mak Yin-Ting.

Yesterday, nearly three years after he left Hong Kong for Guangzhou that fateful April morning, Mr Ching made his return journey home. There were tears, there were smiles. For now, the questions can wait.

suinoi@sph.com.sg