A new group which aims to cut the number of people who die in custody will publish its first report today.
The Forum for Preventing Deaths in Custody will publish statistics on fatalities in police custody, prison, approved premises, immigration custody and among those held under the Mental Health Act.
Members will also make recommendations to improve the way people are held in a bid to cut the death toll.
It comes after the number of prison inmates who have died in suspected suicides has begun to rise dramatically.
Although the annual number of jail deaths had fallen in recent years so far in 2007 there have been 68 deaths compared with 46 at this point last year.
The forum was set up last year and its remit also covers deaths which occur after release from prison, as well as "near deaths" which may provide scope to boost prevention measures.
There were around 600 deaths in custody last year, including in prisons, young offender institutions and police cells.
Of those, around 400 were from natural causes and 200 self-inflicted, a spokeswoman for the Ministry of Justice said.
There were 67 self-inflicted deaths in prisons in 2006, falling from 78 the previous year, she said.
Juliet Lyon, director of the Prison Reform Trust, said the number of suicides this year was "very disappointing".
"The Prison Service have been working rather well to try and reduce risk and respond better to vulnerable people.
"But the level of overcrowding now is such that a lot of those efforts have been swept away," she told the BBC Radio 4 Today programme.
Moving prisoners constantly from prison to prison was a key factor, she said.
"If you are mentally ill or unstable or under stress, you are constantly faced with uncertainty - staff who don't know you, you're further from home, you've got no support systems and you feel like you are in some sort of hell."
Mentally ill people should be given healthcare instead of being imprisoned, she urged.
The Forum's chairman, John Wadham, said local lessons learned from individual deaths were not being shared across the system.
"The challenge for everyone is to make sure that those lessons are learned, not just within the Prison Service generally but within the other institutions."
Deaths were a "trauma" for staff as well as families and friends, he pointed out.
He welcomed efforts to remove things from cells that people could hang themselves on, but warned that the report had found suicidal people could be "very inventive about where they can attach ligatures".
The mother of the youngest child to die in custody in the UK accused the Government of doing too little.
Carol Pounder's son, Adam Rickwood, was 14 when he hanged himself with his shoelaces while on remand at the Hassockfield Secure Training Centre in County Durham in 2004.
The teenager had been restrained with a controversial "nose distraction technique" which involved him being punched in the face.
She told Today: "The number of child deaths in custody is shocking.
"The Government is failing to provide adequate support. They do not have enough properly qualified, fully trained prison officers in these children's institutions.
"They have nine weeks' training and that's from learning which key opens which door, what number to put the washing machine on, to looking after these young children... the most vulnerable of young children.
"In an adult prison, the training course is a lot longer."
Justice Minister David Hanson welcomed the report and said that while the number of suicides had gone up, the proportion of the prison population taking their own lives was dropping.
"There is a need for greater continuity between different agencies, there is a need for work between the police, between the community, assessing people and assessing risk. We are doing what we can.
"It is difficult. There will always, unfortunately, probably be suicides in detention. What we need to do is identify and work with people to reduce that.
"History shows, with our figures over the last three years, that proportionally that figure is dropping.
"That's not to be complacent. I want to make sure."
He said a review of restraint of children had been set up in the wake of Adam's death.