A 23-year-old man has been charged with possessing explosives.
Police say the man is being held at a Yorkshire police station
Peter Stephen Hill, a risk analyst, from Skipton, North Yorks, was charged under the Explosive Substances Act and will appear in court on Monday.
He was detained on Wednesday in Leeds by Metropolitan Police officers and a domestic and a business property were searched in Skipton.
Police released Mr Hill on bail, pending further enquiries under the Official Secrets Act.
The Metropolitan Police said the man would appear in custody at Leeds Magistrates' Court on Monday.
The Yorkshire Post reported the man was originally arrested under the Official Secrets Act, for allegedly attempting to pass military information to Russia.
The paper said the breach of security was related to a government rather than a commercial source.
The explosives charge is understood not to relate to any suspected terrorist-related activity.