The only clue was microscopic traces of DNA, found on the centre console and the rear passenger seat of the BMW.

forensic officers found traces of the same DNA found in the police car in Heilbronn.

And it was here, 15 years ago, that the search for the Woman Without a Face began - with a DNA sample on the rim of a brightly painted teacup.

It next appeared five months later, just a few dozen miles from Bad Kreuznach, on a discarded heroin syringe.

DNA taken from an abandoned biscuit outside matched the Woman Without a Face.

It was later abandoned, and when it was tested, her DNA was found on the petrol cap.

In Karlsruhe in 2005, there was a late-night robbery at a bar. Her DNA was found on two beer bottles and an empty wine glass.

A member of the local gypsy community turned a 7.65-calibre pistol on his brother, and police promptly arrested the gunman - only to find, after forensic checks in Wiesbaden, that the mystery woman's DNA was on one of the bullets.