In his spacious, modern office on the campus of the University of the District of Columbia, President Robert L. Green proudly displays photographs of civil rights leaders whom he has counted among his closest friends: the late Dr. Martin Luther King Jr., as well as Coretta Scott King and Atlanta Mayor Andrew Young.

Green marched through hostile crowds of whites in the Deep South during the mid-1960s with Martin Luther King. Through Coretta Scott King, Green maintained active ties with the civil rights movement after the marches and tough street battles were over.

And today, with Andrew Young, Green is linked to the elite of the nation's black political leaders.

For years, those relationships have served as Green's bridge between the often disparate worlds of politics and academe.

Now the UDC president is counting heavily on his reputation and skills as a civil rights activist and as an educator at Michigan State University to save him from the most damaging controversy of his 25-year career. The FBI last week began an investigation into alleged financial improprieties by Green and other officials at the university. D.C. Auditor Otis H. Troupe last week accused UDC officials of "stonewalling" his inquiry into university financial practices and said Green owed UDC $13,000 in funds that he has spent improperly since taking over the 13,000-student land-grant university in September 1983.

Green, 51, a native of Detroit, acknowledged in a 45-page report to the UDC trustees last month that he has made some mistakes. He said he inadvertently violated some university and District accounting procedures, primarily because he tried to get off to a fast start before learning all the proper procedures. He said he mistakenly used UDC funds to cover personal expenditures, and he has repaid some of that money.

But Green insists that much of the controversy over his administration's handling of finances has been overblown by Troupe and overly aggressive news media that, he contends, have overlooked the "great strides" made by UDC since he became president.

"I believe UDC is a great institution, and that is not written about," Green said last week in defending his administration's record before a local group of journalists.

"When I accepted the presidency of UDC two years ago, I knew it was not going to be an easy job," Green said. "I believe UDC will continue to be challenging and demanding and will continue to grow."

Green declined to be interviewed for this story and has turned down other requests for interviews. He was last interviewed by The Washington Post in early June.

Since taking office, Green told the journalists last week, he has cleaned and spruced up the university campus on upper Connecticut Avenue NW. He said he put in place a "strong, competent administrative team," including a number of former colleagues at Michigan State University in East Lansing. He said he has been aggressive in raising money for a new Applied Research Center at UDC. And he boasted that the university was reaccredited this summer by the Middle States Commission on Higher Education.

Green's arrival here two years ago raised the expectations of the 15-member board of trustees, the alumni, the faculty and the students, many of whom had grown weary of turmoil and drift at the young university under Green's predecessor, Benjamin Alexander. Alexander resigned as UDC's second president after 10 months as a result of controversy over his academic programs and political leadership.

Under Green, his supporters say, the administration became more responsive to students. Green and his wife Lettie, who have three children, showed commitment to UDC by offering to pay the tuition, fees and book costs for several scholarship students each year. Earlier this year, Green spoke optimistically of raising standards and enlisting the support of local high-technology companies to provide classroom and on-the-job experience for promising students.

But Green's flamboyant and often combative style, honed during his days as a civil rights activist, and his decision to hand out jobs and contracts to longtime associates, have made him unpopular with some UDC officials and faculty. One top official complained privately that Green routinely challenges aides whom he suspects may be disloyal and that he uses "intimidation tactics" to sidetrack critics.

Green has rankled some with what they consider his "lavish" life style. Under a five-year contract, Green receives an annual salary of $74,900, the use of a university-owned house in Upper Northwest Washington with two full-time housekeepers, and a chauffeur-driven car. Grumbling among some UDC officials and staff about Green's extensive use of a number of university accounts to finance personal expenditures ultimately led to Troupe's audits and media reports showing, among other things, that Green had used public funds to send flowers for personal reasons, to finance personal travel and to hand out contracts and jobs to longtime friends and associates.

In an interview with WRC-TV (Channel 4) Thursday, Green said that the controversy over his expenditures was largely the result of "unfair" news reports. "I have done nothing dishonest," he said. "I have not abused the public trust."

His friend Andrew Young said, "I don't think any of us who know Bob Green would believe that he would do anything dishonest or self-serving . . . . The worst that anyone would think of him is that he didn't turn in receipts on time or neglected to do adequate accounting."

Young, who is one of Green's most ardent supporters, said in an interview last week that Green is "courageous to the point of being foolhardy," sometimes willing to take chances that others might consider unwise or impractical.

Green has characterized recent criticisms of him as similar to attacks against black leaders who tried to desegregate housing and dormitories when he first arrived at Michigan State in 1960 and who later marched with Martin Luther King in Mississippi and Alabama.

"There was pressure at Michigan State when a black could not buy a home in East Lansing," he said. "I provided the leadership [even] though there were those who put pressure on me for that attempt to desegregate housing in East Lansing.

"Pressure is not something I am unfamiliar with," he said. "I'm familiar with pressure night and day."

But Green's critics, including Troupe and several members of the UDC board of trustees, said that the president is trying to cloud the issue. The real problem, they say, is that Green's administration has mismanaged UDC finances and that the growing controversy and the FBI investigation are dragging the eight-year-old institution to its lowest point.

Five of the 15 trustees have indicated that they think Green should resign or temporarily step down, according to interviews conducted during the past 10 days by The Post.

Trustee Donald A. Brown yesterday became the third of those five board members to express his concern publicly. Brown urged that Green be placed on administrative leave.

"He wants to bring the whole university down with him," one of the five trustees said bitterly.

In a speech at the opening convocation of UDC's faculty and staff Friday, Green's usual intensity gave way to a gesture of appeasement: He invited faculty and staff to review documents of his expenditures on travel, entertainment and household furnishings.

"Come up to the third floor and look at the catering bills," he said. "Look at any of the other bills. Look at the consulting bills."

A trustee who supports Green, but asked not to be identified, said, "He genuinely feels that if people really know Bob Green, this wouldn't be happening . . . . He thinks, whether he is right or wrong, that people will see that he is a guy who is not doing anything bad."

Some top officials said Green has become detached from UDC faculty and students. He has surrounded himself with a number of longtime friends or associates, including his current spokesman, Gilbert Maddox, who is a former colleague from Michigan State.

Green's inner circle consists of two former proteges from Michigan State, Maxie C. Jackson and W. Louis Stone, whom he recruited to be UDC provost and budget director, respectively. Another longtime friend, Chester Higgins, was hired to write articles and press releases portraying Green in a positive light.

Some of Green's critics complain that the president has exaggerated his accomplishments. For example, Green said last week that he was responsible for attracting $1 million in grants for the new Center for Applied Research and Urban Policy. However, other university officials said that about $700,000 of that money is part of an eight-year-old grant from the D.C. government for training programs.

Similarly, critics said that more than half of the funds that Green said he has raised in scholarship money has come from one of his friends, Connecticut businessman David Chase, who has pledged $10,000 annually for the next 25 years.

At Michigan State, where Green earned a doctoral degree in educational psychology in 1963 before joining the faculty, he became the first black dean and one of the first blacks to buy a house in East Lansing.

"Bob Green has always had a lot of people resist him," said a former assistant who worked with him in the College of Urban Development. "He alienated people but he was trying to do good things."

Green took a leave of absence from Michigan State in 1966 to work with King's Southern Christian Leadership Conference. He helped register blacks to vote, and he marched with King, Young and Stokely Carmichael to protest segregation in the South.

Green became a minor celebrity during an emotional march in Granada, Miss., shortly after the shooting of James Meredith, a black student who tried to enroll at the University of Mississippi. Green climbed onto a statue of Jefferson Davis and planted an American flag in his hand.

Upon returning to Michigan State, Green helped establish a college of urban affairs. His academic work largely centered on desegregation patterns in urban school districts. His work became the basis for many metropolitan desegregation lawsuits during the past 15 years as well as a reorganization of the Detroit police force.

But he remained a civil rights activist, often at the center of controversy. He led students in a 45-minute disruption of a Michigan State basketball game to protest discrimination within the Big Ten -- an act described as "intolerable" by then-university president Clifton Wharton, who is black.

In 1975, when Green and Young traveled to South Africa with tennis star Arthur Ashe, Green recruited black South African students to attend Michigan State and arranged scholarships for their education that he says the university initially opposed.

Green attracted a loyal group of students and young faculty members, including Maddox, Stone and Jackson. Later, he and several colleagues established a cable television firm that bid unsuccessfully for Detroit's cable franchise two years ago. Green and his family lived in one of the most exclusive neighborhoods in East Lansing, which is about 70 miles from Detroit.

"In the early days, people like me signed on with Bob because we believed in the mission and vision he had," explained Lawrence Lezotte, chairman of Michigan State's education department, who said he was indebted to Green for helping advance his career. "What began to happen was that the ends and the person got turned around. The person became the mission."

Some former colleagues and UDC officials said that Green's experience in Michigan may have failed to prepare him for his role in Washington, where he has a more prestigious job but lacks a significant constituency or political clout.

"He doesn't realize that here he is one of six or seven college presidents in a highly political town," said one UDC administrator who declined to be identified. The current controversy has mushroomed, the official said, because Green lacks a political safety net and has relied on his friends from Michigan to help him through the crisis.

Others have said that Green is caught between roles as a social activist and academician, unsure where he really belongs. "He has never been able to figure out whether he is a civil rights leader or an educator," said a top UDC official who is critical of Green.

Higgins, a former editor of a NAACP magazine who has known Green for more than 20 years, described Green as a "fascinating person. He's a first-rate scholar, and he has the tough inner core of a Detroit street dude," Higgins said last week.

Clearly, Green has aroused emotions and controversy throughout his career.

"At Michigan State he was something of a firebrand," said a former administrator. "He was one of the black faculty who took an aggressive position on just about every issue that came along. In the end he would come out fairly reasonable, but the tactics in between could be aggravating. He had a talent for rubbing people the wrong way and being confrontational."