Classified documents, allegedly from Iran, reveal secret research into how a cyber attack could be used to sink a cargo ship or blow up a fuel pump at a petrol station.

The internal files, obtained by Sky News, also include information on satellite communication devices used by the global shipping industry as well as a computer-based system that controls things like lights, heating and ventilation in smart buildings across the world.

The papers appear to reveal a particular interest in researching companies and activities in western countries, including the UK, France and the United States.

A security source with knowledge of the 57-page bundle of five research reports said it was compiled by a secret, offensive cyber unit called Shahid Kaveh, which is part of Iran’s elite Islamic Revolutionary Guard Corps’ (IRGC) cyber command.