Austin Aylward, shown in a family photo, died in March 2008 at Her Majesty's Penitentiary. (CBC)

An investigation has been ordered into how an inmate died in custody in St. John's last year.

Austin Aylward, 31, died at Her Majesty's Penitentiary in March 2008, in a case where foul play was ruled out but where an autopsy could not determine its cause.

The government has asked retired judge Robert Wells to conduct an independent investigation into Aylward's death.

Aylward's family said the man had been diagnosed with depression and bipolar disorder, and should have been held at the justice ward of the Waterford psychiatric hospital, and not at the penitentiary.

Another inmate, James Walsh, said last year guards were called to Aylward's cell minutes before he died, after Aylward was heard making choking noises. Walsh said he believed Aylward was alone at the time. He also said the guards removed Aylward from his cell, and were visibly disturbed after Aylward died.

Wells will interview police officers, corrections officers and other officials, and will submit a report directly to Justice Minister Tom Marshall.