Auckland lawyer Ron Mansfield has written to the Minister for Justice saying detoxification centres are needed to prevent more deaths in police custody.
Sentry Taitoko died in February at the Manukau police station where he had been taken to sober up.
In a 2012 report, the Independent Police Conduct Authority said of the 27 people who died in custody in the previous decade, almost half were intoxicated, a third were on drugs; and half had a mental illness.
Mr Mansfield said there's a desperate need for a separate medical facility for those people to be assessed when arrested.
He said people are dying needlessly while the issue is not addressed. He has prepared an 18-page proposal.