A criminal slander case was reportedly launched in September in the Caspian province of Kalmykia against Yelena Baturina, according to RBK.
Baturina reportedly did not show up to the trial and is being represented by lawyers.
Russian law allows defendants in minor criminal cases to be represented by their lawyers.
But in the statement required by the court for such approval, Baturina reportedly did not explain why she could not attend the court hearings in the town, which is 1,200 kilometers southeast of Moscow. She also reportedly neglected to date the document.
The lawsuit arose from a decade-old dispute between Baturina and her brother Viktor Baturin, the former first vice president of her company Inteco.
During a hearing in Vienna about their dispute, Baturina said that Erentsen Manzheev, a financial director for Baturin, was under criminal investigation. Manzheev said that was false and filed a lawsuit against her.
Baturina is one of Russia’s richest women, having built her fortune during the 1990s and 2000s when her husband dominated Moscow politics.
Inteco received sizable Moscow city contracts, raising questions about a possible conflict of interest.
Luzhkov, who was fired by then-President Dmitry Medvedev in 2010, died earlier this month at the age of 83.