Children were a big commodity after WWII, especially if they could raise them with the proper education:
Missing Children
The issue of the missing Yemenite and other Jewish children is well-known in Israel, but surprisingly, it is virtually unknown abroad. In the years 1948-1954 thousands of Jewish children were taken, sometimes forcibly, from their biological parents while in hospitals or child-care homes.
These children were taken to institutes and kibbutzim, and many were given out to adoption. The adopting parents not only changed the childrens names, but also their I.D. numbers, so they would not be able to be traced. These activities were carried out by doctors, nurses, social workers and other members of the Israeli establishment at that time.
Their parents however were told that the children had died. In most cases, when the parents asked about the cause of death or requested a death certificate, or other documentation confirming the death of their children, they were ignored and their requests went unanswered. They never saw a body. In most cases, not even a burial spot. In a few cases, however, graves were shown to the families. Some of those graves, later on, were dug up by parents who did not believe that their beloved, healthy child truly died overnight. The graves were found empty.
Some say that people in positions of power at the time that the State of Israel was established profited from the abduction and sale of children from poor immigrant families. Others claim they wanted to deny those children the education that their religiously observant parents would provide them, and sent them to secular kibbutzim and institutions to get a "modern" secular Israeli education.
These children were not only Jews from Yemen, but also from other middle eastern and european countries. The number of kidnapped children has been told to be around 2,400 by the official investigating committees. Some people estimate the number to be as high as 10,000 missing children.
Ahavat Israel - Missing Jewish Children