Ching Cheong, Chief China Correspondent for Singapore's The Straits Times newspaper, speaks in this undated photo

The Chinese government says a Hong Kong reporter jailed for more than a month in Beijing has confessed to spying. Advocates, however, question the government's charges.

Chinese Foreign Ministry spokesman Kong Quan on Tuesday said Ching Cheong, a veteran reporter with the Singapore newspaper The Straits Times, admitted to the charges while in detention over the past several weeks.

"He already admitted that in recent years he engaged in intelligence-gathering activities on the mainland on instructions from foreign intelligence agencies, and accepted large amounts of fees. Of course we have full evidence," said Kong Quan. "He himself admitted this."

The Chinese official gave no answer when asked for what foreign country or agency Mr. Ching, who holds a British passport, is accused of spying.

The press freedom advocacy group Reporters Without Borders in Paris has called on foreign governments to pressure China to release Mr. Ching. Vincent Brossel, head of the group's Asia-Pacific desk, says there is no evidence to date that Mr. Ching might have been tortured. However, he says the group questions the means by which the government might have obtained a confession.

"When you detain someone for a month and you put pressure on his family, you put a lot of pressure on him, it's obvious you can get some confession," said Mr. Brossel. "I don't know exactly what is the content of his confession. We just hope that the lawyer will get access to him, and also that his trial will be fair."

Singapore Press Holdings, the owner of The Straits Times, said in a statement that unless it sees evidence otherwise, it believes Mr. Ching "always acted in the best interests of The Straits Times."

British consular officials in Beijing on Tuesday indicated they had not yet been allowed to communicate with the journalist and had no information on his condition.

Chinese agents arrested Mr. Ching on April 22 in the southern Chinese city of Guangzhou. People close to Mr. Ching say he had traveled to mainland China to collect documents related to Zhao Ziyang, a purged Communist Party leader who died in January.

Advocacy groups say China continues to be the nation with the world's highest number of journalists in prison. China's spying laws are quite strict and much information that is public knowledge in many countries, such as social welfare statistics, is considered secret in China.

Ching Cheong is the second employee of a foreign paper who has been arrested in the country over the past few months.

Zhao Yan, a New York Times research assistant has been jailed since September. Authorities arrested him on charges of divulging state secrets and later accused him of fraud. His imprisonment has prompted inquiries from U.S. Secretary of State Condoleezza Rice and her predecessor, Colin Powell, who called for his release.

Mr. Zhao, a Chinese national, has yet to go on trial.