A government security breach involving secret documents that were left on a London commuter train has not jeopardized national security interests, British officials said Thursday.
The breach was traced back to a Cabinet office senior intelligence official who has been suspended pending an inquiry.
The documents assessing al-Qaida's vulnerabilities and the capabilities of Iraq's security forces were discovered by a passenger on a London commuter train Tuesday. The passenger then passed the documents to the British Broadcasting Corp.
Prime Minister Gordon Brown promised a full investigation.
"We take this seriously and of course any breach of intelligence cannot be condoned," Brown told reporters Thursday. "We will have to trace where these documents have gone, if they have gone anywhere apart from in an envelope to a local BBC station."
At least one page of the documents was stamped June 5, indicating the assessments were recent.
There was no evidence the breach threatened national security, said Ed Miliband from the Cabinet office.
"There is no evidence to suggest that our vital national security interests have been damaged or any individuals or operations have been put at risk," Miliband said. "While the documents do not contain the names of individual sources or specific operational details, they are sensitive, high-level intelligence assessments."
Britain's Official Secrets Act prohibits individuals from circulating secret information.
Government rules also forbid the removal of secret documents without authorization and compliance with security procedures.
"No authorization was sought for the removal of the documents," Miliband said.
Two of the assessments were made by the British government's Joint Intelligence Committee. The report on Iraq was commissioned by the Ministry of Defence. The al-Qaida report was commissioned by the Foreign and the Home Offices.
The assessments often include intelligence material gathered from agents on the ground.
The BBC has said it could not reveal the documents' exact contents after receiving legal advice.
Government data losses
The security breach is the latest in a string of government data losses and comes as Britain pushes for an expansion of its national DNA database — already the largest per capita in the world — and works to finalize plans for an ID program.
A computer containing sensitive details on 600,000 prospective military recruits was snatched from the car of a Royal Navy recruitment officer in central England in January.
The data included details of candidates' religions and some banking records. It was not encrypted.
In another breach, tax officials last year lost computer disks containing information — including banking records — on nearly half the British population.
"There can scarcely have been a graver breach of intelligence and security procedures than this," said Francis Maude, a spokesman for the Conservative Party.