Chief Constable Sir Hugh Orde has warned that high levels of scrutiny could cause problems for the PSNI.
Speaking at a justice conference in Co Antrim, he said the effect of the number of outside agencies examining the police could become "dysfunctional". Sir Hugh has stressed since his first day in office that he welcomes oversight and constructive criticism from others.
However, he told The Irish Timeson arriving in Belfast in 2002 that the levels of monitoring could impede good policing.
"There's Stevens [ the inquiry he joined into RUC-loyalist collusion]; the Oversight Commissioner; there's some major crime advisers; there's her majesty's Inspectors of Constabulary about to look at us in relation to Special Branch and into how we manage crime. We'll have eight, nine, 10 groups of people looking, pulling us apart, while we are trying to get ourselves organised," he said at the time.
He returned to the same theme at yesterday's conference in Templepatrick. "We are the most accountable police service, probably in the world, and I have no difficulty with that," he said. But he added: "At some stage a question needs to be asked of when does oversight become dysfunctional?" He warned that problems could arise if senior officers spent more time and resources examining official recommendations than investigating crimes against the public.
Speaking at the same conference, Kathleen O'Toole, head of the Garda Inspectorate and a member of the Patten Commission, said she was hopeful that the thorough reform of policing could be realised.
"My hope continues to be that all of the goals we established during the Patten Commission work will be realised," she said.
Referring to Sinn Féin moves to endorse the PSNI and policing systems on both sides of the Border, she added: "Certainly policing in Northern Ireland has come a long way in recent ways and I am optimistic that progress will continue."
Kit Chivers, Chief Inspector of Criminal Justice in Northern Ireland, also said police accountability was the key to reform. "With Sinn Féin on the Policing Board there will be scope for consolidating the progress that has been made, without them it will be difficult to achieve the comprehensive support for policing across the community which the community itself needs," he said.
Looking to the future and the effects of the Review of Public Administration he warned: "There is going to be a financial squeeze for the justice system and it will become imperative to find ways of delivering greater effectiveness in terms of law and order with static or diminishing resources."