A former senior official of Sinn Fein recently exposed as a British spy has been found fatally shot in northwest Ireland, police said Tuesday.

Donaldson, Sinn Fein's former legislative chief in the failed power-sharing government of Northern Ireland, admitted in December he had been on the payroll of the British secret service and the province's anti-terrorist police for the previous two decades. He then went into hiding — because the traditional Irish Republican Army punishment for informing is death.

But Ireland's national police said it was not clear whether Donaldson, 55, had been killed or had taken his own life. In the statement the force said the scene around his body in Glenties, County Donegal, was cordoned off for a forensic examination planned for Wednesday.

A Catholic-Protestant power-sharing administration for Northern Ireland — the central goal of Northern Ireland's 1998 peace accord — fell apart in October 2002 because of an IRA spying scandal with Donaldson at its heart.

Donaldson, his nephew and a British civil servant all were charged with pilfering documents from inside the power-sharing government that identified potential targets of the outlawed IRA and detailed political opponents' private conversations. Protestants at the time accused the IRA of plotting a potential resumption of its violent campaign to oust Northern Ireland from the United Kingdom.

But British prosecutors mysteriously dropped all charges against the trio in early December. Sinn Fein leader Gerry Adams initially defended Donaldson and the others — but a week later announced that Donaldson had confessed, under questioning by Sinn Fein officials, to being a paid British spy. Within hours, Donaldson admitted this was so in an interview with RTE, the Irish state broadcasters.

The IRA last year declared it was renouncing violence for political purposes and backed the pledge by handing over its weapons stockpiles to disarmament chiefs. Both moves were supposed to spur a revival of power-sharing involving Sinn Fein, the IRA-linked party that represents most Catholics in Northern Ireland.

But Protestant leaders have refused to cooperate with Sinn Fein, citing the IRA's refusal to disband and its alleged involvement in a range of criminal activities.

If police determine that Donaldson was killed, it would be certain to fuel the hostility of the major Protestant party, the Democratic Unionists, to cooperating with Sinn Fein.

The prime ministers of Britain and Ireland, Tony Blair and Bertie Ahern, are expected to announce a new blueprint for reviving power-sharing on Thursday. The joint governments' proposals, which have been 3 1/2 years of diplomacy in the making, recommend that Northern Ireland's legislature reconvene in mid-May and face a Nov. 24 deadline to elect an administration jointly led by the Democratic Unionists and Sinn Fein.