A cross-section through the two holes shows the nature of copper mineralisation which becomes more continuous near the core of the system.
More than $9 million was spent by Barrick PNG Exploration, the operator, in 2010 and plans are underway for further drilling this year.
The prospect is about a four-hour drive from existing infrastructure, including a deepwater port which will be essential for future development.
An agreement between Coppermoly and Barrick allows Barrick to spend $20 million to earn 72% of the Nakru, Simuku and Talelumas prospects.
Meanwhile, recent 3D induced polarisation data has returned a chargeability anomaly about 150m below the surface at Nakru-4.
A chargeability anomaly was also detected over the Nakru-3 copper prospect.