Police in Beijing are promising a "zero-tolerance" policy if police misconduct is found to be a factor in the death of young man earlier this month.

Officers involved in the death of 29-year old Lei Yang insist their actions were justified when he resisted arrest after being busted trying to pay for sex while at a bath house in the northwestern Beijing suburb of Changping earlier this month.

The graduate student died after struggling with police officers who had been detaining him.

There is no video available for either the bust or the subsequent altercation between Lei Yang and the police officers involved, with police claiming both the outside cameras and the camera used during the raid were not active at the time.

The "zero-tolerance" pledge by police in Beijing follows another report of a young college student being beaten for hours by police in Gansu a few days ago following a minor conflict on the street.