The findings come more than 30 years after the last cases of wild polio virus infections in people were registered in Germany and mark the first wild virus detection from environmental sampling in the country since this type of routine monitoring began in 2021.
The World Health Organisation said it was the first such detection in Europe since 2010 and reinforced the message that no country is immune to the spread of polio although the threat of disease in Germany remained very low, largely because polio vaccination rates are high in the country.
"Wild poliovirus type 1 (WPV1) has been detected in a sewage sample in Germany," the Robert Koch Institute said in a statement to Reuters, adding that no infections in people had been reported.
Polio, short for poliomyelitis, is a viral infection that can kill or cause paralysis but which can be prevented by vaccination.
There are two forms of polio circulating globally.
Wild polio is rarer and only present in Afghanistan and Pakistan.
The other form, vaccine-derived, circulates in more countries and stems from rare instances where weakened live viruses used for immunisation mutate and spread.
The Robert Koch Institute added on Wednesday that the risk to Germany's general population from either form of poliovirus is "very low" due to high vaccination coverage and because cases of virus detection in wastewater are only "isolated".
Testing sewage water for the virus is a technique used globally to track the spread of polio.
The Robert Koch Institute has reported findings of vaccine-derived poliovirus from several wastewater samples across Germany since the end of 2024.
A number of other European countries, including the United Kingdom, have also reported vaccine-derived detections in recent years.
However, the WHO said the last detections of the wild form of the virus in Europe were in Russia and Tajikistan in 2010, and in Switzerland in 2007.
Europe was declared wild polio-free in 2002.
The last case of polio infection acquired in Germany through wild viruses was reported in 1990.
The most recent imported cases, brought in from Egypt and India, were registered in 1992.
The WHO said later on Wednesday that the new wild polio detection in Germany appeared to be associated with the strain circulating in Afghanistan.
Oliver Rosenbauer, spokesman for polio eradication at the WHO in Geneva, said the detection mainly showed how well Germany's surveillance network was working.
Some countries do not actively track polio in this way.
The world has been trying to eliminate polio for decades.
Mass vaccination efforts have reduced cases by 99 per cent since 1988 but wiping out the disease completely has proved challenging.