Germany ? German investigators’ search for a mysterious suspected killer has ended with an embarrassing discovery: identical DNA traces common to dozens of crime scenes stemmed from contaminated cotton swabs.

The DNA had been found at the scenes of about 40 crimes over recent years in Germany, Austria and France, ranging from restaurant break-ins to the shooting of a policewoman.

The common DNA prompted police to search for a woman German media called the “phantom killer.”

However, officials said Friday they had determined that the DNA came from an innocent woman at an unidentified Bavarian packaging company involved in producing the cotton swabs used to collect evidence.

“The puzzle of the phantom killer has been solved,” said Volker Link, a prosecutor from Heilbronn — the scene of a policewoman’s fatal 2007 shooting, the most prominent crime linked to the mystery suspect.