Chinese prosecutors have accused police of torturing a young murder suspect to death, while two juvenile inmates have died under suspicious circumstances, state press said yesterday.

Prosecutors in northern Shaanxi province said high school student Xu Gengrong died on March 8 after police tortured him to extract a confession over the murder of a female classmate, the China Daily reported.

China Central Television said in a report on its website that the youth's heart stopped after a marathon torture session.

Meanwhile, the Beijing News said two teenagers were found dead at a juvenile detention centre in central Hunan province over a four-day period in early March.

Six police officers have been arrested over Xu's death, which has played prominently in the nation's press after repeated calls by officials and rights groups to end the alleged widespread practice of torture in China's jails.

There were calls at this month's annual session of Parliament for greater protection of suspects after a Chinese prisoner was beaten to death by fellow inmates.

The UN Committee Against Torture last year expressed deep concern over allegations of widespread torture in China and called on the government to probe rights abuses in its prisons.

In a survey published by the Chinese magazine Juvenile Crime Research last week, 47 per cent of criminal suspects polled said they had suffered police brutality under questioning.

The Beijing News said the parents of the two young men in Hunan suspect police brutality, as the body of one youth had a large open wound and his wrists were black and blue.

Prison officials said the deaths occurred under "normal circumstances", the paper said, without elaborating.