With a rising level of public supervision, China's top police department will make more effort to rid the detention houses under its power of a daunting public profile, reported the China Youth Daily on Monday, quoting an official in direct charge.

The official made the remark as security issues for detention centers holding criminal suspects has aroused enormous public concern in the wake of an inmate's unnatural death early last year.

Authorities will increase the transparency of the regulation of detention houses and expand the public's right to both know and supervise relevant police jobs in the future, Zhao Chunguang, an official in charge of the country's detention houses with the Ministry of Public Security, the top police department, told the newspaper.

Detention centers in China are usually closed to the public for security reasons, and information about these facilities' operations is usually unavailable.

The ministry estimated that it currently has under its power more than 6,000 detention centers that keep millions in custody every year. Some of these detention centers hold criminal suspects, with the rest detaining wrongdoers of minor offences.

But the outside world has gained some insight into the detention centers since the ministry launched a pilot project in May last year to open the doors of 10 centers nationwide to the public on selected dates.

"The move can help increase the public's knowledge of (these places)," said Zhao. "Meanwhile, it will help vindicate the detention houses of some misunderstandings, or even prejudices held by the public."

Authorities say they have seen positive effects produced by the "Open Day" system. At the Xicheng District Detention Center in Beijing, one of the detention houses in the pilot project, "visitors have fundamentally changed their self-invented impressions of us," Zhang Baoli, chief of the detention center, told the newspaper.

Applications for group visits have to be reviewed by the detention center first and then approved by superior authorities, Zhang said.

"Within a week there will be responses from us," he added.

The detention center in China's capital city has received six groups of visitors totaling nearly 200 people since August last year, according to Zhang. They were mainly inmates' family members, journalists and government employees.

It is good and necessary to let the outside world know about the country's detention centers, and the work conducted by the police officers there, Zhao said.