Markus Braun, who resigned on Friday as chief executive of Wirecard, has been arrested in Germany on accusations of accounting fraud and manipulating the payment group’s share price.
He turned himself into Munich police on Monday night after an arrest warrant was issued.
Mr Braun will appear before a judge on Tuesday who will decide whether he will remain in custody, German prosecutors said.
The former paper billionaire has been accused of portraying Wirecard as “financially stronger and more attractive for investors and clients”, prosecutors said.
It comes after Wirecard announced that €1.9bn (£1.7bn) of cash missing from its balance sheet probably did not exist, prompting Munich authorities to open a criminal investigation into the firm.
The company is now scrambling to stay afloat and is in talks with its lenders about extending debt due for repayment at the end of the month, as well as considering a massive restructuring.
On Monday, Felix Hufeld, head of Germany’s financial regulator Bafin, criticised the failings that led to the scandal.
“It’s a complete disaster we’re looking at … it starts with looking at complete failure of a senior management, despite many, many hints to discover the facts,” he said.
“It goes on to the scores of auditors who couldn’t dig up the truth and it goes on with a whole range of private and public entities including my own who have not been effective enough to prevent something like that happening.”
Last week EY said it was unable to find €1.9bn – about a quarter of Wirecard’s total balance sheet.
The cash was supposedly held in trust accounts, but a search for the money hit a dead end in the Philippines.