Berlin police say three baby girls found abandoned in and around the German capital in recent years are siblings.

The first newborn was discovered in Berlin in September 2015, the second in August the following year and the third in the nearby village of Schwanebeck in August 2017.

Berlin police spokesman Michael Maass said Tuesday that DNA tests on the girls showed they have the same mother and likely also the same father.

Police are appealing for information that might help them find the mother because she endangered the children's lives by not using one of Berlin's baby boxes, which allow women to give up their babies anonymously and alert medics to the presence of the infant.

All three babies survived abandonment and now live with foster families.