By Ben Blanchard

BEIJING, June 12 (Reuters) - China's state secret laws are opaque, vague and even a potential threat to human health, according to a new human rights report, which called on Beijing to overhaul the system and stop using it to suppress dissent.

Information can become a state secret retroactively and those charged with violating related laws are often not allowed to have their lawyers present in court, Human Rights in China said in the report.

"The state secrets system allows large amounts of information to be classified as state secrets, employs extensive technological, police and social controls to monitor the flow of information, and places it all under political reins," it said.

"In this complex, arbitrary and encompassing system, anything and everything can be determined to be a state secret, especially under the retroactive classification that the system allows," the New York-based group added.

The "culture of secrecy" led China to at first cover up the 2003 outbreak of Severe Acute Respiratory Syndrome, and also contributed to officials holding back from publicising the effects of a chemical plant blast in northern China in 2005, it said.

In these failures of governance, secrecy continues to be relied upon as a method of maintaining social order and control, to the detriment of the public, the report added.

Human rights activists and other dissidents have been prosecuted using state secret laws, including the now exiled Nobel Peace Prize nominee Rebiya Kadeer, jailed reporter Ching Cheong and blind lawyer Chen Guangcheng, the group said.

In 1994, China sentenced Xi Yang, a reporter of Hong Kong's Chinese-language Ming Pao newspaper, to 12 years in prison for stealing state secrets -- gold production figures and changes in the government's policy on interest rates. He was later paroled.

"Combined with the one-party regime, and the absence of an independent and transparent rule of law in the PRC, the state secrets system allows further consolidation of political and social control by the ruling elite," it said.

China has reformed the system slightly. In 2005, the government "declassified" the death toll from natural disasters, though declined to revise the number of deaths from previous calamities.

Chinese officials have been prone to falsify figures rather than report bad news to their superiors.

Human Rights in China said the government should stop politicising the state secrets system and carry out proper reforms.

"State secrets charges should not be used as a means to silence dissent and inappropriately curtail freedom of expression," it said.

"The politicised use of state secrets charges to silence dissent and the dissemination of 'sensitive' information need to be prohibited and monitored through legislative and agency guidelines and other measures," the group added.

"Revisions should be made to the State Secrets Law and other regulations to eliminate retroactive classification of information."

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