Allegations are currently being investigated in the report that an engineer working on Berlin Brandenburg airport had his coffee positioned for being a whistle blower.
The worker said he was sick for months after he was poisoned, apparently because he was whistle blower in a corruption scandal involving an airport construction firm, according to German newspaper Bild am Sonntag.
The engineer, around 50 years old, collapsed at work and was out of work three months after drinking his coffee.
No suspects have been identified, according to officials and Bild.
Last year, four people were charged as part of the investigation in brides by the construction firm Imtech Deutschland.
The firm filed for bankruptcy in August after being given the task to overhaul the airport's fire and smoke detection system.
Berlin Brandenburg airport is an international airport currently under construction, that is billions over-budget. The airport, originally expected to open in 2017, is projected to be complete near 2019.
But, Dieter Faulenbach da Costa, former chief planner on the site, told Berliner Morgenpost, he doubt the airport would ever open.