A sensational allegation that British spy agency MI5 brought down former First Minister of Northern Ireland Peter Robinson has been made by Phoenix Magazine, Ireland's top investigative journal.

"With 400 officers at its Belfast HQ it is unlikely that MI5 . . . sat on their hands while Robinson gave repeated two-finger signs to Whitehall since he took over from (Ian) Paisley," the magazine reported.

Robinson was forced to step down temporarily after details of his 60-year-old wife's affair with her then 19-year-old young lover were revealed amid accusations that he helped cover up illegal payments to the youth.

Now, Phoenix says that MI5 were likely involved because they wanted to get rid of Robinson, who has been refusing to do a deal to complete the work of the peace process.

Phoenix says that MI5 knew that Iris Robinson had numerous trysts in out-of-the- way places with her lover Kirk McCambley in the back seat of the armored Mercedes car that the government had given Peter Robinson for protection.

They also say MI5 also knew about another affair with a leading politician, a close associate of Robinson, that was taking place at the same time.  "MI5 would have logged in their registry details of her drives around London in her MG sports car with a fun-loving DUP politician,” says the magazine.

The magazine also states that information was provided to the BBC "by a Robinson confidante . . .” that was also in the possession of MI5.

BBC held that information for over three months, but when Robinson again refused to do a deal before Christmas “the anonymous purveyors of information on Robinson played their cards."

The magazine states that the Robinsons fell from power "almost certainly with the help of a hidden hand."