Two women recently were put under investigation, one for possible charges of fraud and the other as a potential accessory to breach of trust, said Joachim Geyer, a spokesman for prosecutors in Braunschweig.
He declined to give details, but said the women were not VW employees.
Wolfsburg-based VW called in prosecutors last year to investigate personnel executive Klaus-Joachim Gebauer, who was fired in June, and former Skoda chief Helmuth Schuster.
The two are suspected of setting up fake companies in countries including India and the Czech Republic to defraud local authorities seeking business with VW.
Gebauer claims he was unfairly dismissed, while Schuster resigned June 15 after being accused.
Authorities are also looking into whether VW managers and members of its works council received illegal privileges including lavish foreign trips paid for by the company, the AP reports.
The FSB of Russia has distributed the footage of video surveillance over suspects, who allegedly worked to orchestrate a military coup in Belarus and planned to assassinate its president, Alexander Lukashenko