The man, who is in his 30s, was arrested on Monday and was later detained on suspicion of violating the law on flammable and explosive goods, preparation for general destruction and weapons offences.
He was released on Wednesday after forensic technicians had made a preliminary assessment of the items seized during the arrest.
The suspicions of weapons offences are still being investigated, but are not grounds for the man to be detained. The other suspicions remain formally, but are weakened.
