The mine at Ndassima is carved deep into a forested hilltop north of Muslim rebel group Seleka's military headquarters in Bambari.
It is owned by Canada's Axmin but was overrun by rebels more than year ago and now forms part of an illicit economy driving sectarian conflict in the country.
At least 27 miners were buried in the collapse of the mine on Thursday and 25 bodies have been retrieved.
At Ndassima, labourers toil beneath the gaze of Seleka gunmen to produce some 15 kilos of gold a month - worth roughly £210,000 on the local market, or double that in international trade.
Thousands of people have died and more than a million fled their homes in Central African Republic amid the violence between the Seleka rebels and Christian militia.