An advocacy group that says Canada's prisons are becoming "bloated human warehouses" has released its own ideas on how to address overcrowding.

The plan includes respecting the presumption of innocence, effectively treating mental illness and properly implementing rehabilitative programs.

A spokesman for the John Howard Society of Canada says overpopulated prisons are an issue across the country, but especially in Manitoba and Saskatchewan.

Shaun Dyer of the society's Saskatchewan branch says the federal government is taking the wrong approach to incarceration.

As a result, he says, there are a lot more people going to jail for longer times and for lesser crimes.

The Canadian Civil Liberties Association released a report in July that said pretrial detention across Canada has risen nearly 300 per cent in the last 30 years.

During the same time, crime rates have declined, with 2012 recorded as the safest year since 1972.