The firm was scheduled to publish Wirecard's 2019 annual report on Thursday but said it would not be able to, because it could not confirm the existence of €1.9 billion in cash balances on trust accounts.
"The company filed for bankruptcy at a Munich courtroom and stated its survival has been" not confident" with $1.3 billion of loans expected next week.
Trading in the company's shares, which have lost more than 95% of their value within days, was suspended in Frankfurt.
Media reports in 2019 called the company's accounting into question, but BaFin targeted investors instead of the firm itself.
Depending on that preliminary probe's results, the Commission could launch an investigation into whether BaFin broke European Union law on financial reporting, Valdis Dombrovskis, the Commission's executive vice president, told the Financial Times newspaper in an interview.
Braun, who denies the allegations, has since been released on EUR5 million bail terms.
- Wirecard's crisis deepened when it said on Monday that the missing sums it had booked in its accounts likely never existed.
The Financial Conduct Authority blocked Wirecard from doing business in the United Kingdom or disposing of assets Brussels called for an inquiry into whether Germany's regulator failed in its supervision of the collapsed payments company.
In its statement, Ernst & Young said Wirecard provided "false confirmations and statements with regard to escrow accounts" in the audit for 2019.
Wirecard's shares have tanked as mounting accounting irregularities have come to light at the former hot tech German startup, which on Friday called in investment bank Houlihan Lokey to evaluate its options.
The move follows the firm's disclosure of a $2.1 billion financial hole in its accounts, which led to the arrest of its former chief executive.
EY, one of the world's "Big Four" accountancy and consulting firms, faces a wave of litigation in a debacle that has drawn comparisons with Arthur Andersen's disastrous oversight of USA energy company Enron.
German financial regulator Bafin, which has filed a revised claim against Wirecard to prosecutors, has parachuted in an official to stabilise its Wirecard Bank subsidiary. Earlier this week, the Wirecard CEO had resigned after termination of a almost $2 billion in debts from its creditors due to the mass-scale mishap at its balance sheet.
KPMG finally reported in April 2020, concluding it couldn't verify arrangements responsible for "the lion's share" of Wirecard's profits 2016 - 2018 were genuine, and citing several "obstacles" to its work.
BaFin has described events this week surrounding Wirecard as a "disaster" and chief Felix Hufeld admitted this week that BaFin "had not been effective enough to prevent something like this from happening".