The acquisition underlines the firm's focus on its exploration efforts near the mine in the Khabarovsk region.
Investors welcomed the news and sent shares up 0.89% to 84.75p in early deals.
The Western Flank, which is 3.9 square kilometres in size, was bought at auction on December 6 for a bid price of around US$280,322.
It includes the highly prospective Chaynoye zone which has good potential to deliver new resources at MNV.
Chaynoye has been previously partially explored and has a historical reported prognostic resource of 3.5 tonnes (112,500 ounces) of gold.
Explored vein widths range between 0.3 to 3.0 metres for up to 115 metres along strike and reported historic gold grades as high as 207 grams per ton (g/t).
Highland has drawn up an aggressive trenching and drilling programme for next year to upgrade the resource potential of Chaynoye for future exploitation.