Weekend reports claiming one of the highest-ranking members of the IRA is a security forces informer have been questioned by former Ulster Unionist security spokesman Lord Maginnis.
The reports claimed a man from Anderstown in Belfast codenamed "Stakeknife" was the head of IRA internal security.
This morning Lord Maginnis, who served as a Special Branch officer for 12 years, suggested the IRA might have been the source of the leak to discredit the British government by implying security services had colluded with informants who were involved in terrorist murders.
He said it would have been "totally justified" for those fighting the IRA to use terrorists as informants if it was possible.
But he told the BBC Radio 4 Todayprogramme: "If you are a republican and in the IRA and you want to discredit the government, you feed this story with the names and we all read it in our papers.
"It's instant news, but instant news doesn't happen in terms of undercover activity of this nature".
He added: "What surprises me about this supposed Stakeknife is that the day before yesterday nobody knew about him - I had never heard of him - and yesterday there are pages after pages of the minutest detail being revealed to the public.
"I begin to wonder in whose interest would this story be?"
PA