HAD Denis Donaldson not been a paid agent of British Intelligence and Special Branch for more than 20 years, the close-knit Irish republican family would have reacted to his death as if one of its model members had passed away.

A “pre-Sixty-Niner” — one who joined the IRA before the eruption of the Troubles — a convicted bomber, a hunger striker, an international ambassador: Donaldson had all the hallmarks of an apostle and he would have been buried with due ceremony in the republican plot in Milltown Cemetery, Belfast, where every Easter the movement renews its vows to end British rule in Ireland.

The irony is that now only time will tell if he really was a model Provisional: the test of that will be how many more of his comrades in the upper reaches of Sinn Fein and the “army” are exposed as informers in the pay of the British.

Donaldson was born into a traditional republican family in the embattled Short Strand, a tiny Catholic enclave in overwhelmingly Protestant East Belfast. Its Catholic parish church, St Matthews, holds an iconic position in Provisional mythology for it was here in June 1970 that Billy McKee, leading a small IRA group in the defence of the neighbourhood, opened fire and killed two Protestant men and a Catholic man.

Donaldson took part in that night’s activities, which finally buried the taunt “IRA — I Ran Away” as the Marxist leadership of the “Officials” was swept away by the Provisionals.

Donaldson had joined the IRA as soon as he was old enough, first in the Fianna, the “boy scouts” of the republicans. But as Belfast descended into chaos he quickly decided, like many young Catholic men of his generation, that the Provisionals and not the Officials — who favoured forging a non-sectarian alliance with the Protestant working-class — were the future.

He rose rapidly through the ranks. He was Provisionals’ commanding officer in East Belfast when he was arrested during a bombing mission on a bottling plant. He served half of a ten-year sentence in the Maze Prison – Long Kesh to republicans. There a smuggled camera caught Donaldson’s young beaming face as he put his arm around Bobby Sands. It was to become one of the most famous republican images after Sands, elected MP for Fermanagh South Tyrone, starved himself to death in May 1981 for the recognition of political status.

Donaldson took part in an earlier hunger strike, which was called off when it appeared that the Government had granted the prisoners’ wishes. On his release Donaldson took on the Provisionals’ intelligence portfolio and was one of the pioneers of the Adams-McGuinness leadership in holding dual high-ranking membership roles in both the IRA and its political wing Sinn Fein.

In 1981 he was arrested at Paris-Orly airport while travelling on a false British passport from Lebanon. Before his release he admitted that he had been visiting Palestine Liberation Organisation training camps.

In 1983 he stood unsuccessfully in Belfast council elections for the east of the city. It was during this period that he was secretly recruited as a British agent.

In his recent confession Donaldson described it as “a vulnerable period” in his life, but the mystery of his recruitment remains. The Irish feminist Marie Mulholland recently described him thus: “Denis stood out, all five foot nothing of him. Yes, he was a small man but somehow it never seemed to matter because he had charm — buckets of it. Not the schmoozing of an operator, but real charm; a blend of wit, generosity, mischief and that capacity to make you feel like you, your problem or your request were the most important thing to him right at that moment. It worked wonders with women, and Denis loved women — lots of them.”

Donaldson once told the journalist Brendan Anderson that British Intelligence had tried to recruit him while he was on holiday in Spain with his wife. “He was not asked if he had declined the offer to work for the British — in retrospect a serious omission,” Anderson wrote.

Over the following years Donaldson travelled widely, taking charge of the republican movement’s international relations, forging close links with “brother liberation struggles” in the Middle East and the Spanish Basque Country.