A son of IRA murder victim Jean McConville has said Gerry Adams warned of a "backlash" if he released the names of those he believed were responsible.

Michael McConville said his family's fight for justice would go on after the Sinn Féin president was freed, but maintained he could be shot if he disclosed the identities of suspects to police.

Adams, 65, was released from Antrim police station, pending a report being sent to prosecutors, after four days of questioning about the notorious 1972 killing of McConville and other alleged links with the IRA.

McConville told BBC Radio 4's Today programme: "Gerry Adams says to me, 'Michael, you are getting a letter of support from the republican people'. He says, 'if you release the names I hope you are ready for the backlash'.

"I took it as a threat."

Adams has vehemently rejected allegations made by former republican colleagues that he ordered the mother of 10's abduction and killing – denials he repeated on Sunday night.

The decision whether to charge him with any offence will be made by the Public Prosecution Service (PPS) at a later date after reviewing evidence presented by police.

McConville alleged the "threat" was made at about the time a report being drawn up by Northern Ireland's then police ombudsman, Nuala O'Loan, into claims that his mother was an informer was close to being finalised.

The Sinn Féin president had brokered a series of meetings between him and members of the IRA. McConville said he used to tell Adams what had happened in the meetings and warned him that he would release the names of those involved if O'Loan's report was disputed. At that point he said the backlash was mentioned.

McConville said that "could" have meant a backlash against the peace process but said he took it to mean the "backlash from republican people".

Adams will refocus on election campaigning on Monday as the political fallout from his release from police custody continues to reverberate around Stormont and beyond.

Sinn Féin is holding a European election rally in Belfast on Monday, with a similar event planned in Dublin on Tuesday, as Adams resumes the canvassing activities he claims his detention was designed to thwart.

The rapturous welcome Adams received in a west Belfast hotel on his first public appearance after his release was in marked contrast to the angry scenes outside the police station as loyalists protested at the decision to free him.

There was disorder in the loyalist Sandy Row area of Belfast, with petrol bombs and stones thrown, though no one was injured.

The former MP for west Belfast and now representative for County Louth in the Irish Dáil criticised the police's handling of his arrest but moved to dispel any suggestion that Sinn Féin's commitment to policing had wavered in the wake of the affair.

Adams's arrest on Wednesday triggered a bitter political row at Stormont, with Sinn Féin accusing an "anti-peace process rump" within the Police Service of Northern Ireland (PSNI) of orchestrating the detention with the aim of damaging the party ahead of European and local government elections later this month.

This was angrily rejected by political rivals, whose fury intensified when senior Sinn Féin figures indicated that their support for the police – a critical plank in the peace process – would be "reviewed" if Adams was charged.

The Democratic Unionist Stormont first minister, Peter Robinson, denounced the remarks as "bullyboy" tactics.

Downing Street confirmed that the prime minister, David Cameron, and the Irish taoiseach, Enda Kenny, spoke on Sunday to discuss the situation surrounding Adams's arrest.

Adams questioned the timing of his detention and said police had unnecessarily used "coercive" legislation to detain and question him.

• This article was amended on 6 May 2014. An earlier version referred to the Irish dail, rather than the Dáil.