A 40 year-old man arrested in connection with the double bomb attack near Derry City Council offices a year ago has been released unconditionally.
The arrest followed the release of CCTV footage on Monday showing a man walking a bicycle near the Rover Foyle before casually retracing his steps without the bike.
Two bombs were left, one in a rucksack and another attached to a bicycle, near Derry City Council building in September last year.
The rucksack was discovered by a Foyle Search and Rescue volunteer before 11pm on Thursday September 20, 2012.
Shortly after that discovery, police who had been called to the scene discovered a secondary device attached to a bicycle chained to a railing just a short distance away.
Neither device exploded.
Police said the man arrested was questioned at Antrim Serious Crime Suite.