Natalia Fileva, 55, was aboard a single-engine, six-seat Epic-LT aircraft that crashed in a field on approach to a small airport at the town of Egelsbach in southwestern Germany, according to investigators and the airline operator, S7 Group.
Fileva's fortune was estimated by business publication Forbes.ru to be nearly $600 million.
Egelsbach is roughly 6 miles south of Frankfurt.
German police said there appeared to be three people aboard the plane, including the pilot of the flight, which originated in France. They said that positive identification of the occupants would require further investigation.
German aviation investigators were looking into the cause of the crash.
German police previously stated that two more people died in a collision with a police vehicle responding to the scene.
The dpa news agency, citing police, reported that three people in the police vehicle were seriously injured in the traffic crash while the two people in the other car died.
"S7 Group team extends sincere and heartfelt condolences to Mrs. Fileva's family and loved ones," the company said in a statement. "The memory of her as an inspiring and sympathetic leader and a wonderful person will forever stay in the hearts of all S7 Group employees. It is an irreparable loss."
The Associated Press contributed to this report.