The number of people who died in police custody reached its highest level for five years in 2014/15, watchdogs have revealed.
There were 17 fatalities during or after detention in England and Wales - six more than the previous year and the highest annual total since 2010/11, figures from the Independent Police Complaints Commission (IPCC) showed.
There were also 69 apparent suicides after release - 50% higher than the in 2010/11.
Home Secretary Theresa May has launched a review into deaths in police custody, saying they have the potential to "dramatically" undermine relationships between the public and police.
The 17 deaths recorded in or after police custody in the last financial year is "broadly in line with the average" over the last six years, the IPCC said. Last year's total of 11 was the lowest since recording began in 2004/5.
Fourteen of those who died were men and three were women and they were aged between 22 and 57. Fifteen were white, one was of Asian ethnicity and one was from a black background.
The number of people believed to have taken their own lives after being in police custody was one fewer than the previous year but there has been an upward trend in the last three years.
Eight of the 17 people who died in or after police custody and half of those who apparently killed themselves had mental health concerns. Drugs and alcohol were also said to be a factor in a number of the deaths.
It was also revealed that:
:: There was one fatal police shooting - the first in three years.
:: There were 14 road traffic fatalities, including seven following pursuits.
:: There were 41 other deaths following contact with the police in a wide range of circumstances, including 26 after concerns were raised about their safety or well-being.
IPCC chair Dame Anne Owers said: "Regrettably, our investigations have too often exposed the same issues: inadequate risk assessments; token checks on a person in custody; insufficient hand-overs between custody staff; a failure to recognise or properly deal with people with mental health concerns or substance abuse issues; poor liaison between police and other agencies."
Setting out the inquiry in a speech in London today, Mrs May said: "Sadly, as these figures show, deaths and serious incidents in custody may be rare, but they do happen.
"And when they do, for the families involved who have lost loved ones, all too often the system doesn't work the way you would expect."
She confirmed the review will not reopen and reinvestigate past cases. It will examine processes surrounding deaths and serious incidents and have the experience of bereaved families at its heart, the Home Secretary said.
Mrs May said the principle of policing by consent centres on a "contract" in which "the police have a responsibility to treat the public with respect, and the public have a responsibility to support the police and respect the work they do to keep us safe".
She added: "And when things go wrong ... that unwritten contract is damaged and the police's ability to maintain law and order is undermined."
Ajibola Lewis, whose IT graduate son Olaseni Lewis died after he was restrained in a south-east London psychiatric hospital in August 2010, accused authorities of "deep-seated and repeated failures".
She said: "If the review is going to be more than an exercise in public relations, and if it is to enjoy the confidence of families in our position, it must find a meaningful way to learn from and reflect our experiences."