In March, it said it was raising upwards of A$5 million (US$3.86 million) for exploration in Colombia.
The company hopes the diamond drilling programme will confirm and expand the gold mineral system previously drilled by a previous owner, as well as test a previously undrilled geophysical anomaly.
Of the three diamond core holes previously drilled, the best hit a 384m intercept grading 1.1g/t gold, 0.9g/t silver and 0.08% copper from surface to the end of the hole.
Intercepts from the other two holes were 340m at 0.4g/t gold , 0.58g/t silver and 0.03% copper, and 255m at 0.51g/t gold, 0.67g/t silver and 0.05% copper.
Metminco said previous drilling had also encountered higher levels of copper and molybdenum as it approached a high chargeability induced-polarisation geophysical anomaly at depth.
The company expects assay results from its drilling in August.