Sinn Féin's Martin McGuinness has claimed that the dark side of policing in Ireland has been acting in "consort" with those targeting the Sinn Féin peace strategy and the party's leader Gerry Adams.
The deputy first minister said: "I view his arrest as a deliberate attempt to influence the outcome of the elections that are due to take place in three weeks time, north and south on this island.
"It isn't that long ago... that we were in fact informed ourselves, by very senior people within the PSNI. People who are quite clearly in tune with the peace process, who are reformers in relation to police, that there was still a dark side within policing here."
He added: "I think we have seen that dark side flex its muscles in the course of the last couple of days.
"We know who they are, the reformers know who they are."
Adams attacks reasons for his detention and denies McConville murder
It is claimed IRA volunteers described what happened the night Jean McConville was murdered to Boston College's "Belfast Project".