Former Volkswagen Group chief executive Martin Winterkorn has been charged alongside four other senior managers over his involvement in the company's diesel emissions scandal.

The public prosecutor in Braunschweig, Germany, charged all four men – four of which were unnamed in an official statement related to the proceedings – with fraud.

Prosecutors accused Winterkorn of a "particularly serious" fraud, as well as a breach of competition laws and insisted that he should have alerted car owners and authorities in Europe and the US about the manipulation of diesel emissions tests sooner.

The legal proceedings in Germany come just a month after the US Securities and Exchange Commission (SEC) begun proceedings to sue Volkswagen and its former chief executive Martin Winterkorn over the alleged defrauding of investors through the dieselgate emissions scandal.

The SEC filed its complaint in the District Court for the Northern District of California on March 14, claiming that VW issued more than $13bn (£9.8bn) in bonds and asset-backed securities between April 2014 and May 2015 – a time when, it alleges, the carmaker’s senior executives were aware that 500,000 vehicles in the country exceeded legal emissions limits.

Quoted in the Financial Times, a Volkswagen Group spokesman described the case against it as “unprecedented” and “legally and factually flawed”, adding that no one involved in the issuance of payments on the bonds at issue knew of the emissions issue.

“By concealing the emissions scheme, Volkswagen reaped hundreds of millions of dollars in benefit by issuing the securities at more attractive rates for the company, according to the complaint,” the SEC said.

The SEC’s suit against VW also seeks to bar Winterkorn, who resigned when the scandal became public in September 2015, from serving as an officer or director of a public US company.

He has been charged in the US with conspiring to cover up the emissions cheating scandal.