On the 24th of October 1976, the remains of a young woman were found at a parking lot off the A12 in Maarsbergen, Netherlands. (This parking lot no longer exists.) The remains were found naked and covered with leaves in a shallow grave.
The cause of death has not been released as far as I can find, however, police believe she may have been held captive for some time before she was murdered due to isotope testing revealing that she had been malnourished. The isotope research revealed that she probably lived between the Ruhr area and the Eifel until she was seven. The period after that must have been in the GDR or elsewhere in Eastern Europe. The researchers think that in the year before her death she was back in West Germany or the Netherlands. Her age at death is believed to have been around 13 - 15 years old.
A cold case team of the Utrecht police has reopened the case and spoke to a witness who said many people at that time knew the girl was dumped in Maarsbergen by two Dutchmen. According to a detective from the cold case team tips about the Heul girl are still regularly received from Germany, Belgium, Poland, Austria, Switzerland, and Croatia.