A 47-year-old man has been arrested by detectives investigating a killing by suspected members of the IRA, the Police Service of Northern Ireland (PSNI) said.
The suspect was detained in West Belfast by officers from PSNI’s serious crime branch and has been taken to a city centre station for questioning.
Father-of-nine Kevin McGuigan, (53), was gunned down in front of his wife in the staunchly republican Short Strand area of east Belfast in August.
A police assessment of the shooting concluded that individual IRA members were involved in a probable revenge attack for the death of former IRA commander Gerard “Jock” Davison, (47), three months earlier.
The murder has sparked a political crisis at the heart of Northern Ireland’s devolved Assembly.
Unionists have pulled all but one of their ministers out of the five party mandatory coalition Executive claiming Sinn Féin was inextricably linked to the IRA.
First Minister Peter Robinson has also temporarily stepped aside while crunch talks to save the Stormont institutions take place.
Sinn Féin has consistently said the IRA no longer exists.
Detectives have previously made a number of high profile arrests in the case including senior republicans, Bobby Storey, Sinn Féin’s northern chairman, Eddie Copeland and Brian Gillen.
All three were released without charge.
Mr Storey’s solicitor said he intends to sue for wrongful arrest.
One man has appeared in court charged with weapons offences.