According to a study by the government's public finances watchdog, more than $400 million in tax advances and loans given to the national treasury by the Democratic Republic of Congo's state mining corporation Gecamines cannot be traced.
Gecamines owns a minority position in Glencore's (GLEN.L) Kamoto Copper Company mine and China Molybdenum's (603993.SS) Tenke Fungurume mine, two of the world's largest copper and cobalt projects.
Corruption allegations have been leveled at Gecamines by non-governmental organizations and opposition politicians for a long time.
Gecamines has consistently rejected any impropriety charges. On Saturday, the organization's secretary-general did not immediately reply to a request for comment on the fresh allegations.
According to an IGF audit report obtained by Reuters, Gecamines presented records to auditors from the General Inspectorate of Finances (IGF) indicating tax advances and loans to the Congolese state totaling $591 million, but only $178 million could be linked to the treasury's accounts.
The missing $413 million was considered to have been misappropriated, according to the report, which was dated May 31 but not made public, and auditors will continue their investigation.
It didn't say when the loans and advances in issue were made.
Another $175 million given to Gecamines as a signing bonus for a copper and cobalt project, according to the report, could not be tracked to the treasury, and the corporation was chastised for failing to independently assess the amount of mineral deposits at its joint ventures with foreign investors.
During its peak in the 1980s, Gecamines produced up to 500,000 tonnes of copper per year, but it has since gone bankrupt and sold off its controlling shares in significant mines.
Congo is Africa's top copper producer and the world's top cobalt miner, which is used in electric vehicle batteries. President Felix Tshisekedi has reorganized Gecamines' leadership since taking office in 2019, removing the executives most directly linked to prior corruption claims.