The Vermont Legislature is investigating the death of a Vermont inmate who was beaten at a private prison in Kentucky and died six weeks later.

The cause of his death remains unclear.

An autopsy completed last month revealed 66-year-old sex offender James Nicholson died of a combination of heart disease and diabetes. But the autopsy lists his manner of death as undetermined because the medical examiner could not determine whether the assault played a part.

Nicholson's skull was fractured in the April attack and his brain bruised. He died May 18.

The Legislature's Justice Oversight Committee will hold a hearing next week to look into his death at the Lee Adjustment Center in Kentucky, run by the for-profit Corrections Corporation of America.