London, June 12 : The British Cabinet office said that senior intelligence official who left secret files on the al-Qaeda in Pakistan and the Iraqi security situation in a train had been suspended from his job.
The government documents were in an orange cardboard envelope, which was left on a commuter train between Waterloo Station in London and Surrey on Tuesday.
A passenger picked it up, realised what was inside and passed the contents to the BBC, which last night handed the documents to police.
The highly sensitive documents were assessments made by the government's Joint Intelligence Committee (JIC). Data provided by the committee can be used to help form future policy and would have been extremely useful to any terrorist group.
Security experts on Wednesday called for whoever had lost the documents to be prosecuted, News.scotsman.com reported.
A spokesman for the Cabinet Office said: "There has been a security breach. The Metropolitan Police are carrying out an investigation." He declined to discuss the contents of the documents.
The BBC said that a "very senior intelligence official" working in the Cabinet Office left the documents on a train from London Waterloo to Surrey. Each page was numbered and marked "For UK, US, Canadian and Australian eyes only".
The document set out the latest government assessment on al-Qaeda, along with a "top secret and in some cases damning" assessment of Iraq's security forces.
It is understood a full-scale police search was launched when it was realised that they were missing, as officials were concerned at the possibility of such sensitive papers finding their way into the wrong hands.
It is the latest in a series of embarrassing losses of government information, including the disappearance of details of millions of child benefit recipients on a disc sent through the post.