In a statement when he resigned last year as chairman of one of the world's biggest engineering and electrical groups, he said he hoped his departure would help calm a media storm over mounting allegations of widespread bribery at the group.
"I have always believed that one's duty to the company and its well over 400,000 employees worldwide must take priority over one's own interests," he said.
"A personal responsibility regarding the current investigations was not the basis for my decision."
Prosecutors said they had no evidence that would warrant criminal charges against von Pierer but that he and other former company officials were being investigated for the administrative offence of breaching their corporate supervision duties.
Von Pierer, 67, was for decades one of Europe's most respected industrialists, advising German chancellors and even considered as a candidate for the German presidency while steering Siemens through potentially turbulent times.
A trained lawyer, he spent all but a few years of his working life at Siemens, once a paragon of corporate Germany where many bright young engineers aspired to a job for life.
His accessible manner and calm authority led many at the trains-to-lightbulbs conglomerate to fear the change that would ensue when the much younger Klaus Kleinfeld - who has also since stepped down - took over as chief executive in 2005.
But von Pierer's unblemished legacy began to unravel in late 2006 when Munich prosecutors said they had raided Siemens offices as part of an investigation into a suspected bribery ring at the company's telecoms equipment division.
The affair, at first said to involve tens of millions of euros and a handful of individuals, quickly escalated. Siemens launched its own investigation into what it now puts at 1.3 billion euros (US$2.01 billion) of suspect payments.
Other criminal investigations into suspected abuse of the United Nations' oil-for-food program in Iraq and bribery of a German workers' association chief followed.
Two former managers were sentenced for bribery in a German court last year, and the energy-to-transportation conglomerate has been fined 201 million euros by a German court in the case.
Siemens is also being investigated by both the Securities and Exchange Commission and the U.S. Department of Justice, with the possibility of high fines or even being banned from public contracts in the United States.
Public pressure mounted on von Pierer, during whose stewardship of Siemens most of the alleged misconduct occurred, to resign, but he repeatedly said he bore no responsibility and knew nothing of the suspected abuses.
At his last annual shareholders' meeting, von Pierer made a concession by withdrawing from a company committee that examines compliance issues, but it was not enough to silence his critics.
Top names at Siemens lined up last year to soften the blow of his departure, paying tribute to von Pierer's personal qualities.
"He served Siemens for many decades with all his abilities and powers and shaped a top international company in a threatening phase," said Josef Ackermann, supervisory board deputy chairman and CEO of Deutsche Bank.