The rig had originally been due to arrive this month at the Nyuni licence to spud the Kiliwani-1 exploration well, after it had a development well on the adjoining Songo Songo gas field.

But mechanical problems meant it had to be sent away for several weeks to be repaired.

Key republished a statement from operator company Aminex, whose chairman Brian Hall said the joint venture had kept itself busy in the region despite the delay.

“Frustrating as this delay has become, we have used the time well to fine-tune our operational procedures, materials procurement and supporting contracts,” he said.

“The delay is outside our control but we may be confident that the rig, once it has passed inspection, will be in first class operational order”.

Key Petroleum, which listed on the Australian bourse in April, will have a 20% interest in the PSC by paying 30% of the cost to drill the two wells.

Fellow Australian junior Bounty will have a 6% stake, while operator Aminex has 39%, RAK Gas has 25% and East Africa Exploration has 10%.