ACPO lead on custody, Assistant Chief Constable Dawn Copley, said:
"The reduction in the number of deaths during or following police contact is noted but the reality is that any death following detention in police custody is a tragedy. We are determined to learn lessons whenever a death occurs and all such incidents are referred to the IPCC for an independent investigation as a matter of course. Individual forces receive IPCC reports on cases following an investigation and take appropriate action where necessary.
"As the figures demonstrate some detainees enter custody with existing or emerging health, mental health or substance misuse problems. Officers and staff receive training and guidance on how to effectively identify, respond to and care for people in these circumstances. They do so extremely effectively in the vast majority of cases in what is sometimes a challenging and difficult operating environment.
"The police service however remains determined to continue to improve the way that people are cared for while in our custody. We share the IPCC concerns in relation to people who die in or after custody and who are known to have mental health problems. We are continuing to work closely with partners to establish more appropriate and coordinated options to better meet the needs of vulnerable people."