Northern Ireland police have been given another 48 hours to interrogate Sinn Fein leader Gerry Adams over a 1972 IRA killing.
Adams' arrest over the killing of Jean McConville was among the most significant in Northern Ireland since a 1998 peace deal ended decades of tit-for-tat killings between Irish Catholic nationalists and mostly Protestant pro-British loyalists.
Northern Ireland Deputy First Minister Martin McGuinness, a Sinn Fein member, defended his ally Adams.
"There is a cabal in the PSNI that have an agenda, a negative and destructive agenda to both the peace process and to Sinn Fein," McGuinness told a news conference in Belfast. Northern Ireland's justice minister denied the accusation.
"I believe Gerry Adams will be totally and absolutely exonerated and I believe that Gerry Adams will continue to lead this party," said McGuinness, a former Irish Republican Army (IRA) commander who only last month met Queen Elizabeth at a Windsor Castle in a sign of normalization since the peace pact.
Reviled by many in Britain as the face of militant Irish nationalism during the IRA guerrilla campaign against British rule of Northern Ireland, Adams, 65, reinvented himself as a Northern Ireland peacemaker and then a leading opposition parliamentarian in the Irish Republic.
But he has been dogged throughout his career by accusations from former IRA fighters that he was involved in its campaign of killings, a charge he has repeatedly denied.
He offered to speak to police about McConville's killing in late March after tapes that apparently accuse him of participation were released by researchers in the United States.
Adams has always denied membership of the IRA and said on Wednesday, when he was arrested, that he was "innocent of any part" in the killing, which he said was "wrong and a grievous injustice to her and her family.”