A 46-year-old man has been arrested under the Terrorism Act by detectives investigating the murder of journalist McKee.
Searches have been carried out at properties in the Northland Road and Creggan areas of Derry/Londonderry this morning (Thursday 6 June).
The man has been taken to Musgrave Serious Crime Suite for questioning.
A number of items were also seized and taken away for further examination.
Detective Superintendent Jason Murphy said since was murdered following violent disorder in Creggan in Derry/Londonderry on 18th April, the police investigation has received widespread support from the community.
“I still want to hear from anyone who has any information and would appeal to the public to contact my team of detectives on 101. Alternatively, if you would prefer to provide information without giving your details, you can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111,” he added.