Sinn Féin has said that a number of its members have supplied statements on the McCartney murder to the Police Ombudsman through their solicitors.
Gerry Kelly, a senior party negotiator, made the claim as the McCartney sisters pointedly questioned Sinn Féin's attitude to the family's demand for justice following the disclosure that a Sinn Féin Assembly candidate had been in Magennis's bar in Belfast on the night Robert McCartney was murdered in January.
Cora Groogan, who stood in Mid-Ulster alongside Martin McGuinness in the November 2003 Assembly election, admitted that she was present on the night but said that she had seen nothing. A statement had been prepared through her solicitor and passed to the Police Ombudsman, Nuala O'Loan.
However, Catherine McCartney said: "Initially, Sinn Féin's first response was that she left the bar at 8.30pm. Then they came back with the statement that she left at 11pm and saw nothing." People could examine the statement and draw their own conclusions, she said.
"Ultimately, this person could have been sitting as a government minister, overlooking policing and justice," Ms McCartney added. "This is an accountable political party. I think people are intelligent enough to figure out themselves whether this is the type of party they want running the country."
Ms Groogan had claimed: "I got to the bar about 10pm that Sunday. I was there for a short while. There was a commotion in the bar, but I witnessed nothing and left shortly after 11pm. I have given a full statement to my solicitor."
Responding to this, the McCartney family said it was not good enough: "Sinn Féin says she has given a statement to a solicitor to pass to the Police Ombudsman. We believe she should give that statement directly to the police or the Police Ombudsman."
The sisters leave for the United States tomorrow to highlight their campaign for justice through a series of meetings with senior political figures including Senator Edward Kennedy, Senator Hillary Clinton and Congressman Peter King, culminating in a meeting at the White House on St Patrick's Day with President George Bush.
The UUP and SDLP yesterday continued to criticise Sinn Féin over its stance on the murder.
UUP leader David Trimble said that the incident proved the nature of relationships within the republican movement. "It just underlines the seamless connection which exists between Sinn Féin and the IRA," he said.
SDLP leader Mark Durkan described republicans' comments as deficient. "Each statement and each measure that they took still was not sufficient, because the questions were still there and they had to return to it," he said.
Mr Durkan's deputy, Dr Alasdair McDonnell, went further. "The truth is that Sinn Féin has been up to its neck in a political cover-up of the truth about this murder. Their only concern has been to limit damage to themselves," he claimed.
The SDLP will raise the issue again today when Mr Durkan meets the Taoiseach in Dublin.