Police in Northern Ireland want to delay disclosing secret reports into security force "shoot to kill" incidents until next year.

The volume of material and complex issues involved were blamed by police after they asked for more time to hand over files to the coroners' court.

Six people including IRA members died in the controversial shootings by the Royal Ulster Constabulary (RUC).

Republicans hit out at the latest hold up. A police spokesman said: "Regrettably the PSNI has been unable to meet the deadline set by the coroner for disclosure of the reports. This is due to the volume and nature of the material to be processed and the complexity of the issues involved."

This comes a week after the police promised to hand over the top secret material. The police service notified the coroner in advance of the "unavoidable" delay. It is understood the force wants the matter deferred until February. The investigation into whether the police set out to kill the six people was conducted by former Greater Manchester Police Deputy Chief Constable John Stalker and Sir Colin Sampson of the West Yorkshire Police. Their reports have never been made public.

The police spokesman said: "The PSNI wishes to re-emphasise its willingness to co-operate fully with the coroner and continues to proceed as expeditiously as possible with a comprehensive disclosure exercise that involves a thorough evaluation of any risks to national security and consideration of human rights issues."

In September Coroner John Leckey gave new Chief Constable Matt Baggott until November 9 to release the never published reports to the Coroner's Court to assist his probe. The alleged shoot-to-kill operations were carried out in the Co Armagh area in the weeks following the murders of three RUC officers in an IRA landmine.

They refer to three separate incidents. One is the shooting dead of IRA men Gervaise McKerr, Eugene Toman and John Burns in Lurgan on November 11 1982. Another is the shooting of Catholic teenager Michael Tighe near Craigavon on November 24 1982. The final incident is the killing of INLA suspects Seamus Grew and Roddy Carroll near Armagh city on December 12 1982.

While Mr Leckey has been given sight of their subsequent reports, he ordered that they were made available to the court so the inquests can finally get under way. The coroner said the Chief Constable could make redactions if he considered them necessary and that he would then examine whether there were grounds to request the disclosure of further details ahead of another preliminary hearing on November 23.

Sinn Fein Policing Board member Martina Anderson said: "Sinn Fein intends to raise the issue as a matter of urgency as we will not allow bad practices of the RUC to be carried through into the PSNI. We are demanding that the Stalker Report is given to the coroner's office immediately so that these inquests can proceed as soon as possible."