Published Wednesday, 28 November 2012
Catholic policeman Ronan Kerr was killed in 2011. (© PA)
The 22-year-old Omagh man was detained in Milton Keynes on Monday following police searches in the area.
A lorry and a number of items were also seized for further examination.
On Wednesday, police revealed they carried out searches in the Dromore area of Co Tyrone as they probe offences linked to the young policeman's murder.
Earlier in the day a 39-year-old man, also from Omagh, was released without charge after being held under the Terrorism Act.
Constable Kerr, 25, was killed by an under car bomb outside his home in Omagh in April last year.
He was a Catholic new recruit to the PSNI and had recently completed his training when he was killed in the explosion at his home in the Highfield Close area of the town.
Dissident republicans have been blamed.