Police have discovered some material which was thought to be explosive when they searched for a suspect in an outbuilding at Bitterne Triangle in Southampton.
The incident happened around 11.30pm last night. A bomb disposal unit was called in to deal with the material.
A police spokesperson said the incident is isolated and involved no risk to the public.
A 28-year-old Southampton man was arrested on suspicion of making an explosive substance. He remains in custody at Southampton Central police station.