Rainer Niedl, retired anti-corruption officer for German multinational Siemens' former telecoms division, admitted during the trial of former executive Thomas Ganswindt that the company paid bribes to win contracts in countries like Argentina, according to international press.
During his testimony at a Munich court, Niedl said the bribes were the only way to do business in many parts of the world.
Ganswindt is being charged with tax evasion and neglect of supervisory duty in failing to prevent a corruption scandal in which Siemens is accused of paying around 1.3bn euros (US$1.8mn), between 1990 and 2007, to win foreign contracts.
In Argentina, it is alleged that Siemens paid millions of dollars to the government for a contract to digitalize identity documents during the presidency of Carlos Menem from 1989-99.
According to the Financial Times, prosecutors in the case argue Ganswindt should have spotted signs that corruption was occurring, while he has denied the allegations. Ganswindt has said he trusted the financial team within the telecoms unit, which he headed.
Several former executives settled last year, with once chief executive and chairman Heinrich von Pierer paying 5mn euros to avoid a legal battle, the Financial Times reported.