Police investigating the murder of Northern Ireland prison officer David Black arrested a 46-year-old man for questioning today.
Police said the unnamed man was from the Lurgan area, close to the M1 motorway where Mr Black was gunned down on his way to work.
Three men, two in Northern Ireland and one in the Republic of Ireland, have been questioned and released by police.
Thousands of mourners lined the streets of Cookstown for Mr Black's funeral on Tuesday (pictured).
Presbyterian Church in Ireland minister Roy Patton said at the service that Northern Ireland would not be "dragged back into the darkness."
The Irish Congress of Trade Unions held a silent vigil to coincide with the funeral to stand against any descent into sectarian violence.
Hundreds of people joined the 15-minute rally outside Belfast Town Hall.
If you appreciated this article then please consider donating to the Morning Star's Fighting Fund to ensure we can keep developing your paper.
Donate to the Fighting Fund here
A government guided by common sense would respond to news that publicly owned Royal Mail has increased profits to £403 million by scrapping plans to flog off the service.
Wales TUC president sets out the achievements of Welsh workers over the past year - and looks to the battles ahead
Interview with Jeremy Scahill, author of a chilling new exposé of the US's worldwide war without end