David Toren, a Holocaust survivor and patent lawyer who waged a single-minded quest to recover art looted from his family by the Nazis, died on April 19 at his home in Manhattan. He was 94. The cause was the coronavirus.

Mr. Toren had a career as a successful patent lawyer but became a hunter of stolen art when a painting that once belonged to a relative, “Two Riders on as Beach” (1901), by the German painter Max Liebermann, surfaced in a secret hoard held by Cornelius Gurlitt. Well into his 80’s, the quest for his family’s stolen art became his preoccupation.

“We will continue to search for and hopefully locate additional works of art looted by the Nazis,” David Toren’s son Peter said. “My father would have expected no less.”