Internal investigators have uncovered more than 1 billion euros ($1.4 billion) of dubious payments at Siemens' telecom and turbines divisions, far more than previously thought, the Sueddeutsche Zeitung said.
"We're talking about enormous sums," the newspaper quoted a source at the top of the company as saying in a report published on Monday, adding that almost 900 million euros' worth of such payments had been found at the telecom unit alone.
The newspaper said a Siemens spokesman declined to comment. Siemens was not immediately available for comment to Reuters on Monday morning.
Siemens, which has been rocked by criminal and internal investigations into suspected organized bribery disguised as payments to business consultants, said last month it was extending its own investigation.
The company said it was now reviewing significantly more business consultant agreement payments than before and was now looking at such payments at its turbines, power distribution, transport, medical and industrial services units.
Previously, Siemens had said it was investigating whether some 420 million euros had been spent on bribes to win telecoms equipment contracts.
The scandal surrounding the investigations forced the resignation of Siemens' chairman and chief executive earlier this year. Peter Loescher took over as CEO at the start of July.