The total new JORC complaint estimate is 17.97 million tonnes containing 1.67 million ounces of gold at an average grade of 2.90g/t.
Within that, indicated gold reserves jumped by 82 per cent to 831,000 ounces at 3.01g/t, with inferred ounces of 841,000 at 2.79g/t.
Nyota said the jump in indicated resources reflected an increased understanding of the geology and structure at the deposit following its latest in-fill drill programme.
This latest estimate also only includes assay results up to the end of January. Data received after that will be included in another resource estimate due later this year.
Richard Chase, chief executive, said: “The resource drilling completed between June and the end of December last year focused on increasing confidence in the geological model so as to convert Inferred Resources to Indicated Resources, as well as increasing the overall contained gold without a significant change in tenor.
“Both of these objectives have been achieved,” he said.
Nyota will now focus on further boosting the indicated resource at Tulu Kapi through a drill programme designed for the margins of the current indicated resource.
Opportunities also remain for the delineation of additional resources immediately adjacent and proximal to the Tulu Kapi deposit including the North and NE Extensions, UNDP and SW Extension, Nyota added.
“While drilling is currently focused on engineering and hydrogeology for the Definitive Feasibility Study, our geology department and Wardell Armstrong are designing a new drill program to target the conversion of a large part of the Inferred Resource that surrounds the current Indicated Resource that is at the heart of the conceptual open pit. Drilling of this programme is expected to commence in the second quarter of the year," Chase added.
Tulu Kapi is bounded by a series of faults with various orientations dominated by the Bedele Shear, which defines the eastern and southern boundaries of the known deposit, the firm added.
Recent drilling has enabled it to model these structures in more detail and establish unique fault bound blocks of mineralisation, which have been individually modelled by independent consultant Wardell Armstrong, it said.
Nyota also released an estimate of the resources at a Tulu Kapi with a geometrical mine plan based on using 2.5 metre high benches.
That plan reduced indicated gold ounces to 792,000 at a 1.88g/t, with inferred resources at 774,000 at 1.83g/t, though the company said this is for guidance only.
Nyota recently raised nearly £10 million through a share placing backed by fellow gold group Centamin (LON:CEY).Centamin now owns own 14.08 per cent of Nyota.