The Shtarkes agreed to look after Schumacher; after settling in Jerusalem and joining the local Breslov community, they sent him to a religious boarding school.
[2] The grandparents decided to hide the boy within the Haredi community in Israel, and Nachman Shtarkes, together with his son Shalom, arranged for Yossele to be hidden from his parents.
Yossele Schumacher was hidden in various Haredi enclaves in Jerusalem, Bnei Brak, Safed, Rishon LeZion, and Komemiyut.
Although initially Zionist, she later adopted Haredi anti-Zionist views and in 1965 married Amram Blau, founder of Neturei Karta.
Shin Bet, the Israeli internal security service, along with Israel Defense Forces soldiers and police, searched for Schumacher in religious neighborhoods, villages, and kibbutzim.
[6] Subsequently, the Mossad began searching for Schumacher internationally, and Harel moved his operations headquarters to a Mossad safe-house in Paris, and sent agents to infiltrate Haredi communities throughout France, Italy, Austria, and the United Kingdom, then expanded the search to South America and the United States, but their efforts to infiltrate these communities proved difficult.
During their investigation, Mossad agents abducted Rabbi Shai Freyer, a teacher at the yeshiva Schumacher was studying in, as he traveled between Paris and Geneva.
He refused to divulge anything during intense questioning, convincing the agents this was another dead end, but Harel ordered him held prisoner in a Mossad safe house in Switzerland (where he was beaten and tortured to try to divulge information but he wouldn't budge), until the end of the investigation to prevent him from alerting the Haredi community.
[6] After getting word that Mossad was searching for Schumacher in Switzerland, Blau took him first to Brussels and then to Paris, presenting the child as her daughter each time she traveled.
The family gave Schumacher the name Yankele Frenkel and kept him indoors, holding him from the time he arrived in March until August 1962.
At this time, Blau had decided to sell her house, and in August 1962 met a potential real estate agent named "Mr. Faber" in an attorney's office.
In September 1962, a team of FBI agents and Mossad operatives took Schumacher into custody and put him on a flight to Israel, where he was reunited with his parents.
The search itself was also an object of controversy, as Harel was criticized for his focus on this case at the expense of manhunts for Nazi officials, notably by then Aman director Major General Meir Amit and even from the Israeli spy Peter Malkin.