DiamondCorp (LON:DCP) said tunnelling into higher grade diamond-bearing kimberlite ore is progressing at originally planned rates following the installation of steel arches that provide a protective canopy.
Resumption of development work on the 290m level began two-weeks earlier than envisaged.
This and the full installation of a conveyor belt used to transport the material for processing have overcome many of the operational roadblocks the firm has faced in recent weeks and months and that have led to delays.
"I am very pleased that these challenges have been met without any injuries to our workforce or damage to our equipment," said chief executive Paul Loudon.