Police abuse of criminal suspects to extract confessions in China is a serious problem despite measures to reform the legal system such as moves to exclude evidence obtained through torture, Human Rights Watch said in a report Wednesday.

The report found that police have found ways around the rules, in a legal system that still relies heavily on confessions to produce convictions in nearly every case, partly because of often inadequate manpower to properly investigate crimes.

President Xi Jinping has made a priority of reducing wrongful convictions and reforming the justice system to restore public confidence in the ruling Communist Party, but has declined to consider loosening the party's control over the judiciary.

A high-profile result of the legal reform campaign so far was the posthumous exoneration in December of a teenager from Inner Mongolia who was convicted of rape and murder and executed 18 years ago. The police officer who oversaw the original case has been charged with using torture to coerce a confession.

Measures put into place in 2009 and 2012 — before Xi became president — require interrogations to be videotaped and ban the use of evidence directly obtained through torture. Those are positive steps, but not enough, Human Rights Watch said.

"They are being grafted onto a criminal justice system that still affords the police enormous power over the judiciary and offers police numerous opportunities to abuse suspects," the group said.

Some officers get around the rules by torturing detainees outside of official detention facilities, using methods that leave no visible injuries and taping confessions later, the report said.

At the same time, police operate the detention centers, suspects have no right to have a lawyer present during interrogations and judges rarely question police conduct and often ignore clear evidence of mistreatment, the report said.

"The confession is still highly valued, a confession is obtained in almost every case, there is nothing that really holds a police officer accountable for torture or coercion," said Maya Wang, Hong Kong-based Asia researcher at Human Rights Watch.

In interviews for the Human Rights Watch report, former detainees, mostly suspected of theft, selling drugs or robbery, described abuse during police interrogations, including sleep deprivation, being beaten with batons and being hung up by the wrists.

The Ministry of Public Security didn't immediately respond to a faxed request for comment.

Human Rights Watch spoke to 18 former detainees as well as family members, lawyers, a former judge and a former police officer. It also looked at 432 court verdicts from across China that addressed claims of torture by detainees among 158,000 verdicts published online from the first four months of 2014. The defendants were convicted in all 432 cases, even in the 23 cases in which judges excluded confessions due to concerns over police torture.

China's Public Security Minister Guo Shengkun was quoted as saying in June 2013 that coerced confessions had dropped 87 percent in 2012 compared to the year earlier. Human Rights Watch said it did not have enough access to confirm or refute that figure.