Three further men have been arrested by detectives from Serious Crime Branch in Belfast in connection with the murder of Kevin McGuigan.
The men - aged 59-years, 58-years and 45-years - were arrested in north and west Belfast this morning (September 9).
It has been reported that those arrested are Bobby Storey, Eddie Copeland and Brian Gillen.
Detective Chief Inspector John McVea said: “The three males are currently assisting officers at the Serious Crime Suite at Antrim Police Station.”
A total of 16 arrests have been carried out in connection with this investigation to date - and one person was charged.
The others were questioned and released unconditionally.
Police have said the murder of Kevin McGuigan was not sanctioned by the IRA.
A police assessment of IRA involvement in the killing has brought the power-sharing institutions in Northern Ireland to the brink of collapse.
Mr McGuigan, a 53-year-old father-of-nine, was gunned down outside his home at Comber Court in the Short Strand area of east Belfast last month.
He was suspected by some in the republican movement of involvement in the murder of former IRA leader Gerard “Jock” Davison close to Belfast city centre four months ago.
Police believe his killing was a revenge attack by Mr Davison’s republican associates.
Although detectives said individual IRA members were involved in the shooting, they have said there is no evidence to suggest it was sanctioned at a senior level.
Police Service of Northern Ireland (PSNI) Chief Constable George Hamilton has also said the IRA is not engaged in terrorism but instead is pursuing a peaceful, political republican agenda.
The political fallout from both murders has had major repercussions for the devolved Assembly, with crisis talks on-going at Stormont in a bid to save the stumbling institutions.