OTTAWA -- The prison watchdog's annual report calls on the Correctional Service to prohibit the use of solitary confinement for inmates who are mentally ill.

The report also says segregation should be limited to no more than 30 days and says it should not be used as an alternative to the disciplinary process.

Correctional Investigator Howard Sapers says the law is clear that segregation should be used sparingly and only when alternatives have been exhausted.

Sapers says the segregation framework needs to be significantly reformed and not just tweaked.

The investigator also flagged the issue of the disproportionate rates of incarceration for aboriginal people.

The report says aboriginal inmates are more likely to be classified as maximum security, to spend more time in segregation and serve more of their sentence behind bars compared to non-aboriginals.