A man in his 20s was being held in Yorkshire after he was arrested by the Metropolitan Police under both the Official Secrets Act and the Explosive Substances Act.

Police on Saturday confirmed the unnamed man was detained on Wednesday in Leeds.

A statement from Scotland Yard said: "At approx 8.10pm on November 7 officers from the Metropolitan Police arrested a man in his 20s at an address in Leeds under the Official Secrets Act. The man was further arrested under section 4 of the Explosive Substances Act 1883.

"Following an application to court for an extension of custody the man remains in custody at a Yorkshire police station."

A police spokeswoman said she could not comment on reports in the Yorkshire Post that the arrest involved allegations that a man was planning to pass military secrets to the Russians.

According to the paper the arrested man is 23, thought to be British, and recently moved to the Skipton area of North Yorkshire where police have been conducting searches of properties.

It said the alleged breach of security was related to a government rather than a commercial source.

The arrest came just two days after MI5 director general Jonathan Evans said it was a matter of "some disappointment" that MI5 was still having to deal with "unreconstructed attempts" at spying by countries like China and Russia.

He said: "They are resources which I would far rather devote to countering the threat from international terrorism - a threat to the whole international community, not just the UK."