Ching's wife Mary Lau and Singapore's Straits Times newspaper, his employer, maintained his innocence despite the accusations.

Ching, a renowned journalist in Hong Kong, has been held incommunicado since his arrest in a Guangzhou hotel on April 22.

His wife, who released the news of his detention Sunday, is seeking assistance from Hong Kong political luminaries with mainland connections.

The Straits Times has hired mainland lawyers and is mobilizing its Beijing correspondents in the hope of being able to meet with Ching in detention.

Meanwhile, an international outcry among foreign advocacy groups is building.

``This is an awful development,'' said Ann Cooper, executive director of the New York-based Committee to Protect Journalists.

``We are going to investigate this case very closely and there is certain to be a lot of international concern.

``China is the world's leading jailer of journalists and it has a deplorable record on these matters.''

Two days after his detention was made known and amid a vigorous backlash from surprised colleagues and family members, the mainland's Ministry of Foreign Affairs released a statement saying Ching has confessed to being a spy for ``overseas intelligence organizations.''

``On April 22 Ching was investigated by relevant Chinese departments for being involved in espionage,'' the ministry said in a statement.

``Ching has admitted that in recent years he has been following the instructions of overseas intelligence organizations and has undertaken intelligence collecting activities on mainland China.

``He has collected a large amount of spy fees,'' the statement said, without releasing any specifics.

The ministry's spokesman, Kong Quan, denied that Ching was apprehended as part of a crackdown against the circulation of a manuscript containing remarks from deposed leader Zhao.

When asked about the case, Kong said: ``I can make this very clear to you, Ching's case is totally unrelated to Zhao Ziyang. We are a country with rule of law. We only act on evidence. He has confessed to it.''

Lau on Tuesday described Ching as ``a patriot who has led a simple life'' and has ``no need'' to be a spy. She said there is no cause for him to act against his country.

Ching is a permanent resident of Singapore and a Hong Kong citizen.

Lau accused Beijing of telling ``the whole world'' of Ching's charges even before he is officially charged.

Singapore's Ministry of Foreign Affairs said Tuesday it has ``not been formally contacted by the Chinese authorities'' about the case. Singapore's embassy in Beijing has approached the authorities to inquire into Ching's welfare, said the ministry,

but reiterated the arrest is a ``matter that is not related to the Singaporean government.''

The SAR government said its Beijing liaison office is following up the case. It is understood Ching entered China holding a home return permit - a travel document for Hongkongers visiting the mainland - meaning he is treated as a Chinese citizen under international diplomatic practices.

According to Lau, she contacted the SAR government in early May but officials remained silent until the local media reported the incident.

The Hong Kong Journalists Association criticized the government for failing to inform the public Ching was detained without legal procedures.

According to legal expert Ong Yew-kim, family members should be informed of an arrest within 24 hours under mainland laws.

HKJA honorary secretary Mak Yin-ting said she believes Ching was conducting ``legitimate journalistic work'' during his mainland trip.

``If you know his history, you know he didn't do it. He has very high ethical standards,'' she said.

HKJA chairman Cheung Ping-ling said the mainland authorities should protect Ching's basic civil rights and give evidence to back up the charges.

Ching, the one-time deputy editor-in-chief of Beijing mouthpiece Wen Wei Po, broke with the newspaper in 1989 to protest the Tiananmen massacre.

Lau and his colleagues said Ching was arrested on a trip in which he hoped to obtain a copy of sensitive remarks made by Zhao before he died in January after nearly 16 years of house arrest.

It is understood Lau has contacted members of the Chinese People's Political Consultative Conference for help.

The Straits Times, which only covered Ching's arrest after the case was exposed, said it will try its best for Ching. ``We are shocked by this new accusation,'' said a spokesperson,

adding Ching will be classed innocent until ``incontrovertible evidence'' appears.

dennis.chong@singtaonewscorp.com