Deputy First Minister Martin McGuinness again complained "political policing" when he addressed a rally in west Belfast this afternoon in support of Sinn Féin president Gerry Adams.

Mr Adams is being questioned at Antrim police station for the fourth successive day in connection with the investigation into the murder of Jean McConville in 1972. He was arrested by appointment with the PSNI.

A several hundred people attended a demonstration on the Lower Falls Road which took place beside the new mural of Mr Adams, which described him as “peacemaker, leader and visionary”.

Many leading Sinn Féin politicians such as Gerry Kelly, Martina Anderson, Alex Maskey and Carál ni Chuilín joined the rally.

Many people held up posters of Mr Adams alongside Nelson Mandela stating “Defend the peace process”.

Mr McGuinness told the crowd that there was within the PSNI “an embittered rump of the old RUC”, which was anti Sinn Féin and anti Gerry Adams.

“These people want to settle old scores whatever the political cost,” he claimed.

“We fully support the PSNI in the fair and democratic implementation of policing and justice but our support is a critical support.”

Mr McGuinness said no police force was immune from criticism “if it is acting in a politically biased and partisan fashion”.

“The arrest of Gerry Adams is evidence that there is an element within the PSNI who are against the peace process and hate Gerry Adams and Sinn Féin. They are, what the reformers within PSNI have described to us as the dark side.”

Mr McGuinness described as nonsense accounts by the Northern Secretary Theresa Villiers that there was no political interference in police, and that no one was above the law.

Citing cases such as killing by British soldiers, of civilians, in Derry on Bloody Sunday and at Ballymurphy in west Belfast, he said no British soldier was brought to justice for these acts.

“The indisputable fact is that for 40 years there has been a virtual amnesty for British state forces involved in killing citizens both directly and through state collusion with unionists death squads,” said Mr McGuinness.

He said that republicans stood by Mr Adams who was “a peacemaker, a leader, a visionary”.

He added: “There would be no peace process but for his commitment and dedication. Gerry Adams is committed to moving this process forward. He will not be deterred or deflected and neither will we. The dark side fear him and they fear us.”

SDLP West Belfast MLA Alex Attwood criticised Sinn Féin for staging the rally and said people must stand in support of the McConville family.

He said some people were “on the wrong side of where the great majority of people are”.

“It begs many, many questions that a rally was held this afternoon in the shadow of Divis, from the very place where Jean McConville was taken and then murdered,” added Mr Attwood.

He continued,”How can any organisation think it appropriate to convene a rally around the arrest of a person in relation to Jean McConville’s murder yards from where she was abducted?”

Mr Attwood said the rally was “another example of Sinn Féin displaying fundamentally bad judgment, at the very least, around the recent arrest”.

“Martin McGuinness has raised questions about support for policing. The new beginning to policing was hard won and no one should casually undermine it.

"The comments of Mr McGuinness are a challenge to Irish democracy, that somehow one person is bigger than peace or politics. As before, Sinn Féin are on the wrong side of the people of Ireland. "