Q Radio news
Three of four men arrested by detectives investigating the murder of journalist Lyra McKee have been released
The men, aged 20, 27, 29 and 52, were detained under the Terrorism Act in Londonderry on Tuesday morning.
The 52-year-old remained in custody on Tuesday night.
The 27 and 20-year-olds were released pending a report to prosecutors.
The 29-year-old was released without charge
Ms McKee, an author, was shot dead while observing disorder in the Creggan area of Derry on April 19 2019.
The New IRA claimed responsibility for the murder, which sparked headlines and revulsion across the UK and Ireland.
Senior investigating officer Detective Superintendent Jason Murphy renewed an appeal for information.
"I have always believed that some people within the community know what happened and who was involved," he said.
"I understand that people may be frightened to talk to us.
"I have previously given my personal assurance relating to anonymity for the purpose of this investigation and I renew this assurance today, as we approach the anniversary of Lyra's murder.
"I want the community in Creggan to think about how that horrific attack impacted them personally and how it impacted the entire community.
"We saw widescale revulsion after Lyra was murdered and I remain determined to work with the community and local policing to convert that revulsion into tangible evidence to bring those who murdered Lyra to justice.
"I also know that many people were recording mobile phone video clips that night and, whilst we had a huge response to my initial appeal for those videos, I believe that others may exist."
The force asked for anyone with mobile phone footage to upload it to the Major Incident Public Portal at https://mipp.police.uk/operation/PSNI19O09-PO1.