German state prosecutors have agreed to prolong the custody of an Audi technician following a U.S. governmental request for extradition in ongoing investigations of diesel emissions test cheating, the newspaper Sueddeutsche Zeitung reports on Friday.

Authorities in Germany hereby responded to a plea made by the U.S. Department of Justice for the preliminary arrest of the Italian national Giovanni P. to enable his extradition at a later stage.

Giovanni P. has been held in police custody for over a month as the only suspect to have been arrested in Germany in the course of the "dieselgate" emission cheating scandal.

Questioned by Munich state prosecutors ten times over his alleged involvement in defrauding tens of thousands of diesel car owners, he has raised serious allegations against senior Audi managers. The defendant has also presented authorities with a folder of extensive evidence in the hopes of being released.

The news of judicial cooperation between Berlin and Washington to instead pro-long Giovanni P.'s police custody comes only two days after his defense council filed a complaint against their client's detention.

Giovanni P.'s attorney Walter Lechner reacted with dismay to the development and accused Munich state prosecutors of employing the U.S. plea as an opportunistic means to keep the suspect under arrest. The state prosecutor had consequently made itself a "minion of the U.S. judiciary", Lechner complained.

German justice authorities defended the move as standard judicial procedure. They argued that granting the U.S. request became a necessity under international law in order to prevent Giovanni P. from leaving the country following the lodging of a complaint against his arrest. If the suspect were to travel to his native Italy, for example, the U.S. Department of Justice would be unable to continue its extradition process.

Giovanni P. is one of 50 suspects in the "dieselgate" scandal currently under investigation in Germany, including prominent figures such former Volkswagen CEO Martin Winterkorn.

The Munich state prosecutors responsible for Giovanni P.'s case believe he was a crucial actor in Audi's installation of illicit software to falsify diesel vehicles' emissions levels. In stark contrast, the suspect's defense claims that their client was a victim of scheming executives for whom the low-level technician has become a "pawn sacrifice".

Giovanni P.'s attorneys also rejected the notion that he was a flight risk and stressed that the suspect was keen to remain in Germany and continue to cooperate with authorities there.

The U.S. request for the technician's preliminary arrest raises serious accusations such as conspiracy to commit fraud and breaches of environmental regulations.