Gerry Adams freed without charge after questioning over McConville case

Gerry Adams at a press conference at Balmoral Hotel with Martin McGuinness. Photograph: Jeff J Mitchell/Getty Images

Gerry Adams has been released without charge from a Northern Irelandpolice station but a file on him will be sent to the public prosecution service, it has emerged.

The Sinn Féin president was released at 5.45pm on Sunday from the serious crimes suite at Antrim police station.

He was being questioned about the murder in 1972 of widow Jean McConville. He has denied both any involvement in the killing, and membership of the IRA.

Armoured vehicles and a large phalanx of police officers in riot gear carrying shields moved out of the police station shortly after 7pm. They were deployed to clear dozens of loyalists from the front of the police base who had sat on the road.

But it transpired that the security operation was a decoy to divert the loyalists from the back of the station where Adams and his entourage left by car.

Earlier, the fallout from the row over his arrest produced an angry exchange within the power-sharing executive at Stormont with the first minister, Peter Robinson, accusing Sinn Féin of trying to blackmail the police.

Peter Robinson said he hoped the Police Service of Northern Ireland (PSNI) would not bend to "republican bullyboy tactics".

Robinson said: "The protest action taken by Sinn Féin is unacceptable in any democratic country operating under the rule of law. The publicly conveyed threat to the PSNI delivered by the highest levels of Sinn Féin that they will reassess their attitude to policing if Gerry Adams is charged is a despicable, thuggish attempt to blackmail the PSNI.

"The threat now means that ordinary, decent citizens will conclude that the PSNI and the PPS [Public Prosecution Service] have succumbed to a crude and overt political threat if Adams is not charged. The PSNI must not be the subject of republican bullyboy tactics."

The first minister's remarks are a measure of the acrimony between the two main parties in the regional devolved government, the Democratic Unionists and Sinn Féin, over Adams's detention.

Sinn Féin junior minister and former IRA Old Bailey bomber Gerry Kelly was allowed into Antrim police station to visit Adams on Sunday afternoon.

Kelly said Adams believed his detention was politically motivated and that it had been "mishandled."

Kelly said his party leader was "worried about the damage that it may be doing to the image of policing as well. This is quite a serious situation."

Kelly said that Adams told him that the police also quizzed Adams about books he wrote over the last 40 years and showed him photographs from the Troubles.

The Sinn Féin minister's visit was highly unusual because normally only a doctor or lawyer can visit a suspect in a police station in Northern Ireland.

Separately, a group of Ulster loyalists arrived near Antrim police station where Adams has spent a fifth day being questioned by detectives.

They erected a union flag on a lamp post and carried a placard claiming their right to fly the flag.

The deputy first minister, Martin McGuinness, earlier claimed sinister forces within the police were behind the arrest and were trying to "settle old scores", and said his party would review their support for policing if Adams was charged.

A rally of up to 600 people turned up in west Belfast on Saturday to observe the unveiling of a mural along Falls Road in honour of Adams. The demonstration took place a short distance away from the site of the Divis Flats complex, from where Jean McConville was dragged away 42 years ago and never seen again by her children.

Jean McConville's eldest daughter has vowed to take civil action against the Sinn Féin leader. Helen McKendry said she had been approached by a high-powered legal firm offering their services to pursue Adams through the civil courts. She said the action will be modelled on the case taken by families of the Omagh bomb victims against four named in Belfast high court as leaders of the Real IRA at the time of the 1998 massacre.