A joint national inspection highlighted that too many people suffering from mental disorders were being locked up in police custody rather than being protected in hospitals.
Police have powers to take individuals suffering from mental health issues in a public place to a "place of safety" for their protection although guidance states that in all but "exceptional" circumstances this should be in a hospital or health location.
However, more than 9,000 people in 2011/12 were taken into police custody using powers under section 136 of the Mental Health Act, a joint report by HM Inspectorates of Constabulary and Prisons, the Care Quality Commission, and the Healthcare Inspectorate Wales said.
In Devon and Cornwall, the figure was 767 in 2011/12 rising to 784 last year – almost 3% of all those held in police custody.
The force said 21 of those people spent more than 24 hours in their cells with the average length of detention being 11 hours and 12 minutes.
"It is not acceptable for people with mental health issues to be locked in a cell because there is no other 'place of safety' available," Mr Hogg said.
"Not only is this potentially detrimental to the individual concerned, but it also places a strain on custody centres and police resources at a time when they are already severely stretched. Too often police officers and staff, rather than experienced and trained medical professionals, are dealing with people who have complex mental health needs.
"I am working with the chief constable to identify how my role as the police and crime commissioner can address this urgent problem.
"I already serve on the region's health and wellbeing boards, so I am ideally placed to oversee and procure wider partnership working.
"I appreciate that health, mental health and social services agencies have resourcing issues, but this is something we simply have to address, sooner rather than later."
Problems with a lack of "places of safety" in the force area were publicly aired as far back at 2009.
Chief Constable Shaun Sawyer said it was an issue he had raised with both the Association of Chief Police Officers and Home Secretary Theresa May.
"Police cells are clearly not a place for individuals with complex mental health issues who need support from medically trained professionals, not police officers," Mr Sawyer said.
"Being locked in a police cell could potentially exacerbate mental health issues and individuals should only be detained by police in exceptional circumstances for as short a time as possible."
