A leading British historian has uncovered that the U.K. freed hundreds of Nazi war criminals after World War II, the Jewish Chronicle reports.

Dr. Dan Plesch, director of the Centre for International Studies and Diplomacy at SOAS, part of the University of London, found United Nations War Crimes Commission documents that show former Nazis were freed from British jails after the Holocaust.

According to the documents, Britain freed Oskar Groening, known as the "Bookkeeper of Auschwitz," Erich von Manstein, Gerd von Rundstedt and Albert Kesselring, the Jewish Chronicle reported. Groening was sentenced to four years in prison earlier this month.

Plesch says that the the former Nazi officers were released under pressure from the U.S., which wanted Germany on its side in the Cold War.

“There was a political argument at the time in which those opposed to international criminal justice succeeded There were lots of people who were either released without much investigation — and then there were people who were actually in prison camps and let out. Hundreds of suspects and convicted Nazis [were released],"the Jewish Chronicle cited him as saying.

He added: “Indeed, British jails were empty by 1957 after much pressure from Germany and German army veterans associations who refused to support rearmament against the USSR while they remained in jail.”

According to Plesch, we should learn from this incident, and probe charges of war crimes levelled against countries like Israel and Syria.

“These are very important lessons for our own time states, including Israel, need to give much more serious attention to the importance of international criminal law today," the Chronicle cited him as saying.