German doctors have spoken out against proposals for young asylum seekers to undergo mandatory medical tests to ascertain their age.
The German Medical Association (Bundesärztekammer) said the checks were ethically wrong and unreliable.
Conservative politicians have called for tests such as X-rays to make sure young migrants are not lying about being under 18 to avoid deportation.
It follows outrage over the killing of a girl, allegedly by an Afghan migrant.
The 15-year-old was stabbed with a kitchen knife outside a shop in Kandel, in south-western Germany, last week.