It could have been the biggest private operation of the decade. Its impact on the Holocaust ethos would have equaled the capture of Adolf Eichmann.

Several former senior security officials with proven skills and experience in monitoring, establishing contact, intelligence gathering, and data analysis had already been enlisted. There were several working meetings and efforts were already underway, despite the world financial crisis, to raise funds from foreign donors. The still as of yet unnamed operation would have capped the many years devoted by Dr. Efraim Zuroff, director of the Simon Wiesenthal Center's Jerusalem branch, of locating Nazi war criminals, bringing about their arrest and extradition to their native countries and putting them on trial.

The target was Dr. Aribert Ferdinand Heim, who had merited the title, "the most wanted living Nazi war criminal." But the joint investigation by the German television station ZDF and The New York Times upset the operation.

Earlier this month, the two media outlets publicized the news that Heim, a senior Waffen SS officer, died in the Egyptian capital of Cairo in 1992.

Heim, a native of Austria, was a doctor in the Buchenwald, Sachsenhausen and Mauthausen concentration camps, where he committed awful acts and abused hundreds of prisoners. He would amputate limbs without an anesthetic, and would inject gasoline into the hearts of his victims and use a stopwatch to clock how long it took them to die. In another case, he scraped the tattooed skin off a live prisoner to use as a cover for the camp commandant's chair. On his desk there was a human skull he had chopped off as a souvenir. In 1942, his mistress got pregnant and gave birth to his daughter, Waltraud, who would later play a central role in the efforts of Heim's family and friends to protect him and conceal his whereabouts. After the war, the United States army captured Heim. He remained in a detention camp for two and a half years, but was not identified and eventually was released.

He married and had two children, Rudiger, who still lives today in his parents' home in Baden-Baden, and Christian, who lives in the university town of Heidelberg.

For almost a decade and a half, Dr. Aribert Heim continued working unhindered in his hometown as a gynecologist. But in 1962, after Adolf Eichmann's capture, he grew concerned that the Mossad and law enforcement agencies in Austria and Germany, who had issued an arrest warrant for him, were also on his tail. So he got into his red Mercedes and escaped with the help of relatives and Nazi friends from Germany to an unknown destination.

The search for him never officially stopped, but the efforts to capture gradually waned until 2004. That year, law enforcement authorities in Germany investigated a charge of suspected tax evasion against one of Heim's sons. During the course of the investigation, they came across a bank account in Berlin in Dr. Aribert Heim's name with two million euros in it. Following that, the hunt for him was renewed and the German government offered a reward of $130,000 for anyone with information about him that would lead to his arrest.

The Simon Wiesenthal Center, which two years earlier had launched Operation Last Chance to locate the last of the war criminals, obtained a donation and increased the amount of the reward by another $135,000. Dr. Zuroff persuaded the Austrian government to also contribute another $50,000.

The search changed direction when the Wiesenthal Center received information claiming that Heim may be hiding in southern Chile and living near his illegitimate daughter, Waltraud. In the 1970s, Waltraud married Ivan Diharce, a businessman and building contractor, and the couple settled in the city of Puerto Montt on the Pacific coast. Dr. Zuroff traveled to Chile twice and managed to establish contact with one of Diharce's workers.

He told him that a few days earlier he had met his employer as he was carrying large bags of food. According to the employee's testimony, Diharce told him the food was for one of his elderly relatives. This testimony strengthened the suspicions that the devoted daughter and her husband were hiding the Nazi war criminal.

Zuroff even conjectured where the hiding place might be: a forest preserve on an island not far from the city's coast. Zuroff sailed to the island but discovered to his disappointment that the wooden hut in the heart of the forest was destroyed in a winter storm.

Despite the news, Zuroff redoubled his efforts. He contacted private investigators and former intelligence officials in order to look into the possibility of enlisting them in the effort. In the end, he chose two former security officials who agreed to join the effort.

"I considered this operation a challenging assignment of unprecedented national and moral importance," said one of them, who asked to remain anonymous. Efforts were also undertaken to finance the operation, cut short by the report on German television and in The New York Times.

According to the investigation, Heim converted to Islam in Egypt, called himself Tarek Hussein Farid and lived modestly in a small Cairo hotel, until his death in 1992. He left his body to science, but Islamic law prohibits this. His son Rudiger claimed in the article that he traveled to Egypt to try and smuggle his father's body into Germany so that his organs could be donated to fulfill his will. He said the authorities uncovered the plan and buried Heim anonymously in a common grave. He also has a certificate documenting his father's death that was issued by the Egyptian authorities.

"I'm still not convinced about the veracity of the story," said Zuroff. "Such a document can easily be forged."

Why, he asks, did the son remember only now "to kill" his father. How is it possible to explain the fact that to this day Heim has a bank account? If he died 16 years ago, why was his bequest not distributed and why does it remain in his name at the bank?

One possible answer to this question is that perhaps Heim is still alive and by staging his death, his sons are trying to put an end to the chase after him. Zuroff is also responsible to a certain extent. On his trip to Chile he went to the public about the hunt for "the butcher" of Mauthausen and prompted a lot of media coverage.

Heim and his family may have gotten scared and decided what they decided. Zuroff says in response that he had no choice but to use the help of the media to obtain information and spur interest in the chase.

"It is possible that we will never know the truth," he concluded sadly, "because there is no body and it will not be possible to conduct checks to verify what happened to the last notorious war criminal on earth."