The decision to charge a leading republican with IRA membership is an act of “political policing”, Sinn Fein has claimed.

Hundreds have taken to the streets in Northern Ireland over the arrest of Padraic Wilson, 53, a former republican leader in the Maze prison.

Wilson was remanded in custody last Friday after being charged with offences following the murder of Robert McCartney outside a bar in Belfast in 2005. He stands accused of IRA membership and addressing a meeting to encourage support for the IRA, which he denies.

Robert McCartney, a 33-year-old from the nationalist Short Strand, was stabbed outside a bar in 2005. When police arrived at the scene, an impromptu riot prevented them from properly investigating the murder.

Seventy-one witnesses all claimed to have been in the pub’s toilets at the time of the attacks. Sinn Fein suspended 12 party members and the IRA expelled three members in the aftermath of the incident.

North Belfast assembly member for Sinn Fein, Gerry Kelly, has claimed the arrest will do “damage to policing”. Mr Kelly said that Wilson had supported the peace process and blamed an “old guard” within the PSNI who he said was opposed to change within the organisation.

“Instead of dealing with the issue of the murder of Robert McCartney, seven years later we are now seeing that people who were trying to help are nevertheless being targeted,” he said.

“Throughout the mid-90s and up until his release in 2000, Padraic Wilson played a pivotal role in building support among prisoners for the peace process. Since his release he has continued to play a central role in supporting and developing the political process.

“It is anti-civic policing, it is political in its nature and whoever is making these type of decisions is wrongfully in the PSNI.”

The McCartney family have met with leading figures, including Tony Blair, in their campaign for justice, with Gerry Adams stating in 2007 that anyone with information on the murder should go to the police.

McCartney’s sisters accused the IRA of forensically cleaning the murder scene, confiscating surveillance tapes and silencing witnesses. They also claim that the IRA had offered to execute the men responsible for Robert’s death.

A detective told Belfast magistrates’ court that Mr Wilson is not charged directly in connection with the murder of McCartney – the charges relate to an internal investigation by the IRA following the murder.

He said six witness statements had been received from Mr McCartney’s sisters and former partner accusing him of involvement in the IRA internal investigation following the murder of Mr McCartney.

“It is alleged that Mr Wilson and an unidentified person met with the family in their capacity as members of the IRA and as representatives of the army council of the IRA. That role was carrying out an internal investigation into the murder.”

The detective explained that police objections to bail are based on concerns of “interference with witnesses” and reoffending. The McCartney family say they identified Wilson through “internet research” and claim he is the person who took the lead in addressing the meetings.

Mr Wilson’s lawyer, Peter Madden, said his client denies admitting he was in the IRA claiming: “There are certain proofs for membership of illegal organisations and that is not one of them.”

Sinn Fein’s position on the arrest provoked cross-party condemnation, with SDLP Minister Alex Attwood claiming Mr Kelly’s statements were an “attempt to mislead”.

In 2008, Terence Davison, 51, was acquitted of Mr McCartney’s murder and two other men were cleared of charges connected to the killing.