security prisoners at Westgate Correctional Facility on Thursday.

Yesterday, Prisons Commissioner Mr. Edward Dyer said a senior prison officer was in the process of investigating the "very serious'' incident but that he would withhold comment until a full report was made.

The investigation began last week to probe what caused the "mini riot'' during which maximum security prisoners barricaded themselves into a unit, pulling out fire hoses and smashing doors and windows.

Mr. Dyer said the report would examine officers' responses and why the situation escalated.

"If in the end we have to take action against whomever, anything I might say now could jeopardise that,'' he said.

Tempers flared when a decision to allow a maximum security prisoner to attend his father's funeral was reneged on. The prisoner was put in segregation while fellow inmates protested by erecting barriers, shouting obscenities at officers and destroying equipment.

It is also alleged that prison officers were locked in control rooms.