Questions about IRA double agents that just won't go away
When the Irish Times asked Martin McGuinness about the murder of Frank Hegarty, he told the paper that "the reality is that the past is a very, very dark place for everybody'". He didn't mean just for himself; he denied all wrongdoing and sent out a hint that others could be embarrassed if the full story came out.
"That is not true," he said, denying the family's long-standing claim that he had encouraged Mr Hegarty back to his death at the hands of the IRA.
He added: "The Hegarty family know that. I could articulate in this interview exactly what happened, but if I did that, it would be very hurtful and, indeed, very damaging to the Hegarty family." He claimed one member of the family knew what had happened "and I am not going to put that person in a predicament".
As viewers of BBC Spotlight will have seen on Tuesday, Mr Hegarty was an IRA informer for military intelligence. He was identified because the British authorities passed on details of an arms dump in the Republic to gardai, and it was raided. Mr Hegarty was in the quartermaster's department and he was immediately identified.
At this point, I can reveal some things that were not in Spotlight, probably because of an injunction preventing a former military intelligence handler, who has the details, from speaking. Mr Hegarty was taken to the force's accommodation in England, where his phone was tapped, with his knowledge.
The handler claimed that Martin McGuinness rang frequently and said words to the effect that it would be okay to come home. Mr McGuinness has always categorically denied this. He says he warned the family that he should under no circumstances meet the IRA if he had been an informer.
However, a female relative, whom I spoke to, drove him across the border to Donegal to "clear things up". He was later found shot dead.
There were immediately questions as to why Mr Hegarty was picked to dispose of newly imported Libyan weapons - the programme of importation was the IRA's biggest secret at the time - when he had been put out of the IRA on suspicion of informing years earlier.
If the Force Research Unit handler is right, then audio tapes should be available, and there will be questions to be answered if they are not. This shows how much is at stake for all concerned.
Stakeknife is another can of worms. Spotlight alleged, on the basis of not too much evidence beyond him saying he knew what happened in a secretly recorded interview with Central TV years earlier, that he had been involved in the killing of Mr Hegarty.
Whatever the case, Stakeknife was an extraordinary agent. I learned of his existence in the early-1980s when I worked for the Sunday News. Over the years, I mentioned it from time to time and was regularly denounced for spreading black propaganda about a non-existent British super-spy.
I learned his identity in the 1990s but did not publish it, assuming he would be killed. He told me on the phone that he was no longer an active republican, and I believed this to be the case. He had come under suspicion but, for some reason, had not been touched.
An example of his range was given to me by Eamon Collins, another former IRA member, from Newry, who did not know the man I believe was Stakeknife was an agent, but knew him as the head of internal security.
Stakeknife was called in when the Newry IRA made a number of mistakes, including murdering a car dealer in mistake for a police officer. He made a list of all IRA personnel, arms dumps and resources. Then he told Collins there was no need to change anything, just to be more careful.
This sort of complete oversight, the ability to ask any questions of anybody in the IRA and to decide what happens, gave a decisive advantage to British intelligence.
It makes you wonder why the IRA campaign went on so long and why senior figures weren't caught. I don't envy the 50 UK police officers the task of working that one out.