Markus Braun, who stepped down as chief executive of Adyen competitor Wirecard last week due to possible accounting fraud, has been arrested, the German prosecution reported Tuesday. He is suspected of having boosted both sales figures and the balance sheet in order to appear more attractive to customers and investors.

The former CEO resigned from Wirecard on Friday after eighteen years, after accounting firm EY was unable to give the green light for the publication of the 2019 annual report on Thursday. EY was unable to approve the annual report, because there was 1.9 billion euros on the balance sheet that EY couldn't explain.

Wirecard said on Monday that the 1.9 billion probably never existed. The amount represents a quarter of the total assets of the company.

It was not the first time that Adyen's German competitor made headlines about financial impropriety led by Braun. A year and a half ago, Financial Times ( FT ) revealed that documents had been falsified in order to trick accountants. Wirecard has always strongly opposed the publications of FT .

Braun voluntarily reported to a police station on Monday, the German prosecution writes. He will be brought on Tuesday, after which a judge will determine whether he should be detained longer.