The Government is understood to have launched an investigation into the discovery of classified Ministry of Defence documents at a Kent bus stop.

The BBC reported this morning that it believes the documents – including emails and PowerPoint presentations – originated in the office of a senior official at the Ministry of Defence (MoD).

"One set of documents discusses the likely Russian reaction to the ship’s passage through Ukrainian waters off the Crimea coast on Wednesday," the BBC said.

"Another details plans for a possible UK military presence in Afghanistan after the US-led Nato operation there ends."

The BBC was contacted by a member of the public after he realised that the documents were of a sensitive nature.