The court sentenced the men late Tuesday for the illegal purchase and illegal possession of minerals in Bukavu, the capital of the gold-rich South Kivu province.

The three men, who presented themselves during the trial as simple traders, were arrested in early January in a car.

They were carrying 10 gold bars and $400,000 in cash, all of which was seized.

The Bukavu court condemned the men to prison and handed them a fine of $600,000 for "illegal purchase and possession of mineral substances, lack of transparency, traceability in the exercise of mining activities and money laundering".

The charge of "illicit exploitation of minerals" was not retained, but they were found guilty of "illegal stay" in the DRC.

Their lawyer did not respond to comment when contacted by AFP.

Hundreds of mining companies, most of which are Chinese, extract gold in the resource-rich province without declaring profits and often without valid permits, according to local authorities.

Last year the local government declared it was suspending the activities of mining companies that did not comply with Congolese law.

At the start of the year several hundred people in Bukavu protested against illegal mining in the region, demanding that the country's riches be used to help local communities.

The eastern DRC is abundant with reserves of gold, diamonds and minerals which are widely used in manufacturing mobile phones and electric cars.

This mineral wealth is at the heart of conflicts that have plagued the region for 30 years, which intensified at the end of 2021 with the resurgence of the M23 armed group.

Kinshasa accuses Rwanda of supporting the M23 and of trying to get its hands on the region's resources.