She was 64.
Yorac, who headed the Presidential Commission on Good Government (PCGG) until she retired in April, died in Chicago where she was undergoing cancer treatment, said Nick Suarez, a spokesman for the commission.
Supreme Court Justice Adolf Azcuna, a former law partner of Yorac, told DZBB radio that she recently recovered from pneumonia.
"Lately she was fine, then all of a sudden she was returned to the ICU (intensive care unit) where she passed away," Azcuna said.
Yorac received the Ramon Magsaysay Award, Asia’s version of the Nobel Prize, in 2004. The award foundation cited her "exceptional integrity and rigor, and her unwavering pursuit of the rule of law in the Philippines."
Yorac, widely known as incorruptible and a fearless and outspoken fighter for human rights, passed the Philippine bar in 1963 and taught law at the University of the Philippines, her alma mater.
An anti-Vietnam War protester, Yorac also joined activist groups opposed to the Marcos dictatorship, providing legal aid to victims of human rights violations. In 1972, Marcos declared martial law and Yorac was detained for three months.
After a 1986 "people power" revolt ended Marcos’ 20-year rule, Yorac was appointed member of the Presidential Committee on Human Rights and the Commission on Elections (Comelec), of which she was commissioner from 1989 to 1991. She later headed the National Unification Commission, which laid the foundation for peace talks with communist rebels.
In 2001, President Arroyo appointed her to the PCGG. She was credited with organizing the voluminous documents against the Marcos family and computerizing them for the first time.
Yorac never married and her family has not yet announced funeral plans.
The Comelec has asked Yorac’s family permission to have her remains brought to the main Manila headquarters for a one-day wake.
"If the family would allow, we are hoping that her remains be taken to the Comelec so the poll body could give her appropriate necrological rites and give the employees a chance to pay their last respects to their former boss," Comelec chairman Benjamin Abalos told reporters.
Yorac served as acting Comelec chief during the Corazon Aquino administration until Christian Monsod’s appointment.
Monsod and Yorac succeeded in cleaning up the Comelec’s image as a Marcos rubber stamp and the agency enjoyed the highest credibility under their leadership.
Monsod remembers Yorac fondly as a "good friend and a brilliant lawyer," who warmly welcomed his appointment.
"You could always count on her to do a good job," Monsod told The STAR, adding that he gave Yorac the most difficult jobs.
Monsod said further that Yorac deserves to be interred at the Libingan ng mga Bayani because of her dedicated service to the country.
Yorac’s successor at the PCGG, William Dichoso, said her death was a "great loss" to the country, remarking that Yorac was "the most honest, forthright and competent person I have ever met."
Lawyer Rod Domingo, who represents human rights victims of the Marcos dictatorship, said with her death "the human rights (community) will surely miss an ally in their quest for justice."
Yesterday, the PCGG declared a nine-day mourning period and lowered the flag at half-mast. Black ribbons abounded at the agency’s offices.
Commissioner Nicasio Conti, the acting chairman, said Yorac carried out the PCGG’s mission "with courage, vision and conviction."
"She leaves behind a legacy of dedication, professionalism and integrity in public service," he said in a statement.
A Mass will be held at the PCGG during the mourning period, said PCGG spokesman Suarez. No date has been set yet.
During Yorac’s watch as PCGG head, the government recovered $683 million from Marcos-linked Swiss bank accounts. Marcos and his wife Imelda are accused of plundering up to $10 billion.
The PCGG also secured court decisions favorable to the government over shares worth billions of pesos in San Miguel Corporation, Southeast Asia’s largest food and beverage firm, and in a local bank.
Officials and politicians from both sides of the political fence paid tribute to Yorac.
Executive Secretary Eduardo Ermita expressed the Arroyo administration’s "sadness" at Yorac’s demise, saying they had not known her condition was so serious.
Vice President Noli de Castro said Yorac "led the fight against graft and corruption in the bureaucracy with unwavering passion and integrity. A woman of impeccable character, she will surely be missed. May her legacy of uprightness and sincere public service live on."
Senate majority leader Francis Pangilinan said Yorac should serve as "an inspiration and a guiding light for others" in the public sector.
"At a time when public opinion regarding government officials has sunk to an all-time low, we mourn the loss of one public servant who showed that integrity and probity amongst public officials is not only possible, it is necessary to be truly effective," Pangilinan said.
Senators Mar Roxas, Manny Villar and Ramon Magsaysay Jr. also expressed sympathies to the family of Yorac, whom they described as an exemplary public servant who dedicated her life to good governance.
"She will not only be remembered for her courage, fearless views, and feistiness but for her untarnished track record while serving the government and the Filipino people," Roxas said.
"I deeply mourn, together with our fellow Filipinos, the passing of former PCGG commissioner and Comelec commissioner Haydee Yorac, whose deep love of country constantly guided her work ethic," said Sen. Ramon Magsaysay Jr.
Magsaysay cited Yorac’s commitment to her work and high standard of professionalism.
Villar said Yorac’s passing was a "big loss" for the country, especially in government service where she "exemplifies passion and dedication for her sworn duties and obligations — traits that are truly hard to find nowadays."
"Governments and leaders have changed but Yorac’s unstinting commitment to public service remained; she was a public servant in the real sense of the word," Villar said.
Akbayan Rep. Etta Rosales described Yorac as an "incorruptible crusader."
"Her loss comes at a time when we need exactly the kind of leadership she has demonstrated at the PCGG. She has been nothing but supportive in the pursuit of justice against the Marcoses," Rosales said.
Yorac, born on March 4, 1941, completed her Bachelor of Laws degree at the University of the Philippines.
She took up her Master of Laws degree at Yale University, Doctor of Humanities (honoris causa) at Xavier University in 1995, and Doctor of Laws (honoris causa) at Far Eastern University in 1997.
After leaving the Comelec, Yorac headed the Parish Pastoral Council for Responsible Voting in 2000.
Yorac won several awards and honors, among them the French Legion of Honor in 1995 and the Don Joaquin "Chino" Roces Award for Public Service also in 1995. — AP, Reuters, Sandy Araneta, Mayen, Jaymalin, Christina Mendez, Sheila Crisostomo, Jose Rodel Clapano, Delon Porcalla