During World War II, he served at the Mauthausen-Gusen concentration camp in Mauthausen, killing and torturing inmates using various methods, such as the direct injection of toxic compounds into the hearts of his victims.

[3] In February 2009, after years of attempts to locate him, German television network ZDF had found Heim's passport and other documents in Cairo.

For about two months (October to December 1941), Heim was stationed at the Ebensee concentration camp near Linz, Austria, where he carried out experiments on Jews and others similar to those performed at Auschwitz by Josef Mengele.

[16] Other survivors of the Holocaust referred to Aribert removing tattooed flesh from prisoners and using the skin to make seat coverings, which he gave to the commandant of the camp.

[22] Heim continued to collect and live off the rents owed to him from an apartment block that he owned until 1979, when German authorities confiscated the property.

Following his escape there were reported sightings in Latin America, Spain and Africa, as well as formal investigations aimed at bringing him to justice, some of which took place even after he had apparently died in Egypt.

[22] Efraim Zuroff, of the Wiesenthal Center, initiated an active search for his whereabouts,[24] and in late 2005, Spanish police incorrectly determined he was in Palafrugell, Spain.

[25] According to El Mundo, Heim had been helped by associates of Otto Skorzeny, who had organised one of the biggest ODESSA bases in Franco's Spain.

[32] On 6 July 2008, Efraim Zuroff, the Wiesenthal Center's chief Nazi-hunter, went to South America as part of a public campaign to capture the most wanted Nazi in the world and bring him to justice,[24] claiming that Heim was alive and hiding in Patagonia, either in Chile or in Argentina.

[44] After years of apparently false sightings, the circumstances surrounding Heim's escape, life in hiding and death were jointly reported by the German broadcaster ZDF and The New York Times in February 2009.

[48] In 2012, a regional court in Baden-Baden confirmed that Heim died under the assumed identity of Tarek Hussein Farid in Egypt in 1992, based on papers from his lawyer and testimony from his son.

[1] In its 2013 annual Nazi war criminal report, the Simon Wiesenthal Center disputed the 2012 ruling by the Baden-Baden court, claiming a lack of forensic confirmation of Heim's death.

[50] Israeli author Danny Baz published The Secret Executioners in 2007, in which he claimed that a clandestine organisation called 'The Owl', operating outside of international law, tracked Heim down and assassinated him in the U.S. on an island off the California coast in 1982.

[53] In her novel The Scent of Lemon Leaves (Lo que esconde tu nombre, 2010) Clara Sánchez gives a fictional account of Heim's refuge in Spain.

In the fictional Netflix series Jaguar (Global release 22 September 2021) a group of Nazi hunters attempt to catch Heim in Spain in 1962.