China's parliament has approved a revised criminal procedure law that aims to restrict police powers to secretly detain criminal suspects.

The law, passed Wednesday on the final session of the 10-day National People's Congress, codifies the already common practice of “disappearing” suspects into informal detention centers, where many report being tortured.

Lawmakers scrapped an earlier controversial proposal that would have legalized such detentions for criminal suspects. But the revision still effectively allows police to secretly hold for up to six months anyone accused of terrorism or endangering national security – charges often used to detain government critics.

Joshua Rosenzweig, an independent human rights analyst in Hong Kong, welcomed portions of the new law, including a clause requiring police to notify relatives of those held at unofficial locations within 24 hours of their detention. But he told VOA the law also officially sanctions forms of detention that have a history of being abused by Chinese authorities.

“Under the provisions of the law, the police have very little in the way of actual oversight over their ability to use these measures. There is very little that a detainee can do to challenge their detention. In some respect, the authorities' power has been expanded.”

Rosenzweig says many in China fear that police will continue to simply ignore laws that protect against detainee abuse.

But Wu Bangguo, the National People's Congress chairman, said Wednesday the government will make sure police are aware of the changes.

“We'll make the publicity for the revised criminal law, and get it widely acknowledged and make good preparations for the law enforcement. We'll make sure the law is faithfully carried out, punish the criminals, protect human rights and maintain stability.”

Human Rights Watch said certain aspects of the law – if implemented – could protect the rights of ordinary criminal suspects. Specifically, it mentioned stricter time limits for detentions, better guarantees for access to a lawyer and greater protection for juvenile and mentally ill suspects.

China's official Xinhua news agency said the law also outlaws the collection of evidence obtained as a result of torture.

Forced disappearances are commonly used to silence dissidents in China. Instances of such detentions have increased dramatically in recent months, as Beijing has sought to prevent popular uprisings like those that spread through parts of the Middle East and North Africa in 2011.