Nazi war criminal Josef Mengele hid out for 30 years in South America on meager funds supplied by his family and went to his death unrepentant for eliminating what he called "unworthy lives," according to letters and papers given by Mengele's son to a West German magazine.

In about 50 letters written to his son Rolf between 1968 and 1978, Mengele never admitted any guilt and said it was a pity he was condemned to a fugitive's existence because he could have been one of the world's great medical scientists.

The information sheds considerable light on the fugitive existence of the Nazi physician, known as the "angel of death," who performed gruesome experiments on twins and children and has been charged with responsibility for the deaths of 400,000 persons at the Auschwitz concentration camp.

Mengele's years in hiding, from the time he escaped from Bavaria to South America in 1949, appear from the letters to have been spent mainly in Argentina and Brazil, not Paraguay as many Nazi hunters previously believed.

The cache of letters, notebooks and photographs turned over last week to the popular Munich-based weekly Bunte has been closely scrutinized by four historians from Oxford, Cologne and Frankfurt universities. They concluded that there could be no doubt that the material was authentic, said historian Guenter Deschner, who participated in the inquiry.

Two years ago, Stern magazine, another West German weekly, bought and published the alleged secret diaries of the Nazi dictator Adolf Hitler. In one of the publishing world's biggest hoaxes, the volumes were soon revealed to be crude forgeries.

Norbert Sakowski, Bunte's deputy editor who has dealt personally with Rolf Mengele, said the son did not ask for payment when he handed over the papers last week. Sakowski said the magazine has decided to set aside all profits earned from sales and publishing rights to the Auschwitz survivors' fund.

The younger Mengele, a 41-year-old lawyer from Freiburg, could not be reached for comment. He has stayed in seclusion since the exhumation June 6 in Brazil of the corpse that authorities say may be the remains of his father.

In a statement last week, Rolf Mengele said he had "no doubt" that the body exhumed near Sao Paulo would prove through forensic tests to be that of his father. He said he kept silent about his father's death for the past six years "out of consideration for those who were in contact" with him during his years in exile.

Sakowski said the son finally released the material because he "wanted to end the mystery once and for all" surrounding Josef Mengele's fate so he could live free from public harassment.

The first of a series based on the documents, including accompanying explanations by Rolf Mengele, was made available today in advance of Thursday's publication.

The son said the family always knew where his father was hiding and sent him money in small monthly deposits ranging between $100 and $170. Josef Mengele's father Karl visited him once in Argentina and Hans Sedlmeier, a clerk in the family's farm machinery business in Guenzburg, traveled to see him many times, according to Rolf Mengele.

The son said there was no "Odessa" conspiracy of old Nazis helping his father, and the absence of such a network, he believes, may have enabled his father to elude capture for so many years.

"He lived in poor and miserable conditions; perhaps they were so simple nobody ever suspected him," Rolf told Bunte.

He said he saw his father twice in his life; a photograph shows Josef Mengele on a skiing holiday with his family in Switzerland in 1956, when his son, then 12, was told that "the quiet, friendly man" introduced as Helmut Gregor was an uncle.

Rolf Mengele later visited his father in Sao Paulo in May 1977, when he found the world's most hunted Nazi "a frightened, hounded creature, full of fear, depressed and thinking often of suicide," he told Bunte. A picture from that trip shows Mengele standing next to his son, smiling proudly.

Rolf said he had flown to Sao Paulo under his own identity and with his own passport. There he met Wolfgang Bossert, an Austrian who has said he sheltered Mengele for several years. The two of them, by this account, drove in Bossert's old Volkswagen to the town of Cairus, a poor district north of Rio.

The son recalls being shocked by the relative squalor of his father's life; the house was no more than a wooden shed off a dirty, dusty road. "When we met, my father was shaking with excitement, with tears in his eyes," Rolf said. "I had to conceal my strange uneasiness."

During his 14-day stay, Rolf said his father gave him the only bed and slept on the stone floor. He said they spoke long and often about the possibility that his father might turn himself in to relieve the strain of living underground.

"But for him there were no judges, only those who wanted revenge," Rolf Mengele said. "Besides, he could never understand why anybody could think he should feel guilty for wanting to get rid of what he called unworthy lives."

The son said he "never supported my father in his beliefs, but I did not want to betray him either." West German law does not require relatives to testify against a criminal fugitive.

During their years of regular correspondence, Rolf Mengele said he and his father sometimes engaged in philosophical exchanges about what his father had done during the war and why he felt he could not contemplate facing the verdict of world justice.

"While I cannot hope you will understand or sympathize with the course of my life, at the same time I do not have the slightest reason to try to justify or excuse whatever decisions, actions or behavior of mine," said a letter attributed to Josef Mengele and written to his son. "My tolerance really does have an exact limit, namely when indisputable traditional values are involved, and where I must fear for those who are close to me or for my national community."

The letters, which Mengele began typing after family members complained they could not read his tortuous handwriting, often mentioned home and the Nazi doctor's yearning to return.

Some of the passages were in Latin or Greek, and a special code was used to disguise the identities of relatives or close friends.

Future installments in the series will include descriptions of the four years Mengele spent after the war hiding on a farm near the Bavarian town of Rosenheim.