Mary Treadwell was once one of the leading voices on behalf of the downtrodden in the city-- quoted in national news magazines, married to a city councilman and personally acquainted with judges, congressmen and political and business leaders in the community.

Seizing upon opportunities presented by a federal government bent on helping disadvantaged blacks, she elevated herself from one of the militant voices of the '60s to the leader of Youth Pride, Inc., the best-known minority job training center in the city.

In the process Treadwell moved solidly into the black middle class. She became involved in property management, real estate, and other ventures. She drove a $20,000 car, lived at the Watergate, and vacationed at a $1,000-a-week resort near Montego Bay.

Meanwhile at Clifton Terrace, a dilapidated low-income apartment project owned and managed by one of Treadwell's companies, tenants complained to reporters that they were without heat, electricity, water and sanitary living conditions, and they couldn't understand where their rent money was going.

Tenants at the Kenesaw and Buena Vista apartment buildings, two other low-income projects managed by the same Treadwell company, P.I Properties, had similar complaints.

Then, gradually over the course of months in 1978 and 1979, former employes of Treadwell--particularly former P.I. bookkeeper Zellene Laney--began providing details of how Treadwell and two other P.I. officials, general manager Robert E. Lee and Treadwell's sister, Joan M. Booth, had systematically stolen, misappropriated or diverted to their own use funds that were intended for the poor.

Through a 14-month investigation by The Washington Post, and a nearly 2 1/2-year investigation by a federal grand jury, Treadwell has steadfastly maintained innocence of any wrongdoing.

In long interviews with Post reporters, she acknowledged "some things I would judge as mistakes," but "not theft."

Of the others indicted yesterday, Lee has denied any wrongdoing although he claims Treadwell misappropriated funds, former P.I. official Charles Rinker has denied being involved in or knowing of any wrongdoing, Williams has denied wrongdoing and Booth has declined to be interviewed.

Treadwell, 40, was born Mary Janice Miller in Lexington, Ky., and was raised in Columbus, Ohio, the daughter of a masonry contractor whose business success provided his family with a comfortable existence. She attended Fisk University in Nashville, Ohio State, the Franklin School of Business and Antioch School of Law here. Her first marriage was to a young Naval officer, whose name she has kept.

She met her second husband, Marion S. Barry, after arriving in Washington in the 1960s and joining the civil rights struggles. After four stormy years of marriage and a divorce from Barry, she wed former Youth Pride financial officer Ronald Williams in 1977. He has been living in New Jersey and Treadwell said in a 1979 interview that they were not living together.

Treadwell and Barry, who is now mayor of the District, have said they led separate financial lives while they were married. None of the allegations of wrongdoing, or the charges of the grand jury, implicated Barry.

Since October 1979, when the U.S. Attorney's office began examining Treadwell's businesses, she has maintained a low profile. She has appeared at an occasional fund-raiser for her legal defense, and on television once to refute charges of a former aide, but for the most part, with her businesses now defunct, she has kept to herself and out of the public limelight.

This is in marked contrast to her life style at the height of her power. From 1967 until 1978, Treadwell ruled through a sharp wit, a sharp tongue and her connections with government leaders, instilling fear in those who worked for her and had to deal with her. She appeared at parties of the influential and held forth each year at "Pride Day" parties, which received local news media coverage.

Treadwell sometimes conducted staff meetings that lasted through the night, holding forth for hours while others neared exhaustion. She was quick to fire, and workers aware of her political connections said they feared retaliation from her even years after they had left her employment.

Government officials who dealt with Treadwell were equally intimidated by this forceful woman, according to scores of officials interviewed by The Post.

Said James E. Clay, a former Department of Housing and Urban Development official who is black: "Mary was able to Mau-Mau her way through my predecessors, especially the whites, by coming on strong as a black militant." Others said Treadwell so unnerved officials that they were willing to give her almost anything she wanted to get her to leave a meeting.

Eventually, however, more and more of those who came in contact with her were willing to speak out.

The federal government, which pumped more than $20 million in job training funds into Youth Pride, Inc., stopped the funding after The Washington Post ran a series on Treadwell and P.I. Properties in October 1979.

Youth Pride went out of business last summer. It was preceded in failure by all the other organizations Treadwell had helped found and headed through the 1970s, including P.I. Properties, Youth Pride Economic Enterprises, Pride Environmental Services, Inc., T. Barry and Associates, Inc., and Sticks and Stones Inc.

Lee, 37, came east from California and worked in low-income housing for real estate manager (now City Council member) H.R. Crawford. He joined Treadwell's P.I. Properties as general manager after Treadwell was impressed with his confident manner and ability to grasp HUD regulations.

Lee and Treadwell had a fallout over a real estate venture, Sticks and Stones, Inc., and subsequently each accused the other of stealing from P.I. Properties.

In an interview with The Post in 1979, Lee acknowledged stealing one of Treadwell's tax returns from the Youth Pride office at 1536 U St. NW and claimed she vastly understated her income when she reported $40,000 a year. "She made more than that from P.I. alone," Lee said. "I could send her to jail."

Treadwell told The Post in 1979 that she had reviewed the P.I. books and found that Lee had stolen "something under $15,000" from the company.

In interviews with The Post Treadwell would not disclose her net worth or her annual salary. Lee, while officially paid less than $30,000 a year when he was with P.I., declared in a personal financial statement in August 1979, the year after he left Treadwell, that his net worth was $243,700, with interests in eight properties and 187.5 ounces of gold.

Booth, 27, the younger of the sisters, idolized Treadwell and carried out her instructions, sometimes helping herself to tenants' rents for clothes and home improvements, according to those interviewed in The Post's investigation.

Rinker, 41, a former theological student, was an officer of P.I. and other Treadwell organizations, before leaving to work for the federal government at ACTION. He conducted an unsuccessful campaign for a seat on the Arlington County Board in 1979.

Williams, 38, was a member of the Plainfield, N.J., accounting firm of Williams, Williams and Ellois when Treadwell called upon him to conduct an examination of P.I. Properties books in late 1976. She told HUD officials that he would be doing an audit, but according to HUD officials Williams never submitted any papers backing up what he had done. Lee alleged that Williams had removed P.I. Properties records. In an interview, Williams said, "That's a bit absurd."