German news magazine Der Spiegel revealed that the US National Security Agency has been collecting sensitive data on key telecommunications cables between Europe, North Africa and Asia, which include Thailand and neighbouring countries.

The magazine, citing classified documents from February of this year, described the agency’s success in spying on the so-called Sea-Me-We 4 undersea cable system.

The massive bundle of fibre optic cables originates near the southern French city of Marseille and links Europe with North Africa and the Gulf states, continuing through Pakistan and India to Malaysia, Singapore and Thailand.

Spiegel said the companies that hold ownership stakes in it included France Telecom, now known as Orange and still partly government-owned, and Telecom Italia Sparkle.

According to reports, NSA specialists had hacked an internal website belonging to the operator consortium to mine documents about technical infrastructure including circuit mapping and network management information.