On 18 January 2012, ATC error resulted in two aircraft on procedural clearances in oceanic airspace crossing the same waypoint within an estimated 2 minutes of each other without the prescribed 1000 feet vertical separation when the prescribed minimum separation was 15 minutes unless that vertical separation existed. By the time ATC identified the loss of separation and sent a CPDLC message to the A340 to descend in order to restore separation, the crew advised that such action was already being taken. The Investigation identified various organisational deficiencies relating to the provision of procedural service by the ANSP concerned.