Ambassador Isabel Machik Ruth Tshombe has been ordered to return "before January 15, 2023", Foreign Minister Christophe Lutundula wrote to the diplomat on December 27.
The order followed suspicions of "financial misappropriation in which your personal responsibility seems implicated for an amount of 2,653,142.76 euros ($2.8 million) in 11 months" of running the embassy, he said, following an audit last month.
In particular, he asked her to account for a "treasury deficit" of around 1.8 million euros ($1.9 million) in passport, visa and other administrative fees from January to November.
He accused her of "transforming the embassy coffers into a private kitty", illegally granting herself and other diplomatic staff handsome financial privileges.
Tshombe rejected the charges on Twitter on Saturday, describing the note from the foreign minister as "drenched in acid" and an "abuse of power."
Corruption is endemic: the country ranks 169th out of 180 nations in the 2021 Corruption Perceptions Index by NGO Transparency International.