The individual who lost the documents cannot be named
The Cabinet Office official who left top-secret documents on a train in June is to be charged under the Official Secrets Act, the BBC has learned.
The man was on secondment from the Ministry of Defence when he left two highly classified documents on a train from Waterloo, London.
The documents were passed to the BBC before being handed over to the police.
The employee is being charged under clause 8.1 of the act, which deals with safeguarding information.
It is the least sensitive charge under the act and there is no suggestion of criminal intent.
BBC defence correspondent Frank Gardner said the move would have come as a surprise to many in Whitehall.
"They will have thought this was being dealt with internally at the MoD and Cabinet Office," he said.
The Crown Prosecution Service recommended the official should be charged by the Metropolitan Police due to the highly sensitive nature of his work on the Joint Intelligence Committee.
The documents the individual, who cannot be named, misplaced contained classified assessments about al-Qaeda and the capabilities of Iraq's security forces.
He was informed of the decision on Monday morning and was moved from his home to an undisclosed location.