"In the context of the fight against corruption and financial crime triggered by the Malian government, six judges and judicial officers were charged with forgery, fraud and extortion," a justice ministry official told AFP.
The Supreme Court confirmed yesterday's arrests and told AFP that other cases against "unscrupulous judges" were being investigated.
A source close to the case said the suspects were accused of abusing their position to extort money from Malian citizens or to take part in other forms of corruption.
A 2012 report by the Washington-based think tank the Carnegie Endowment for International Peace Foundation spoke of "state complicity with organised crime" as the main factor enabling the rise of armed Islamist rebel groups in the north.
Keita said earlier this week that he had referred around 100 cases of corruption and financial crime to the courts.
The president pledged in the run-up to his election in August to lead a "relentless struggle" against corruption.