A man arrested in connection with the murder of a prison officer in Co. Armagh has been released.

The 46-year-old from Lurgan was the 4th man to be questioned and freed without charge.

52-year-old David Black was shot dead on the M1 motorway as he drove to work last week.

A funeral service took place for him this week at Molesworth Presbyterian Church in Cookstown.

On Monday it was reported that his family had requested that the Northern Ireland Deputy First Minister did not attend the service.

A Sinn Fein spokesperson says Martin McGuinness would have been happy to attend if the family requested it however it is believed they do not want him there.

Dissident Republicans are being blamed for his murder.

Police in the North have offered an reward of stg£10,000 (€12,544) for information leading to a conviction.