Cortes W. Randell, who gained notoriety when he went to prison two years ago in the National Student Marketing Corporation scandal, has emerged as a controversial figure in a bankrupt Virginia real estate investment firm now under investigation by the Securities and Exchange Commission.

The defunct firm, most recently known as National Commercial Credit Corp., has listed $4.7 million in debts and only $207,004 in property holdings in a bankruptcy statement filed in U.S. District Court in Alexandria. Charles B. Sullivan Jr., the firm's lawyer, says its assets, when finally calculated, actually may amount to $50,000 or less.

More than 100 men and women, including many present and former Virginia residents and several retired peesons, invested their savings in the firm's bonds and notes. These investors have begun to file claims against the firm amounting to hundreds of thousands of dollars. Mich money also is owed to banks and other lending institutions.

Acccording to court testimony and interviews with persons familiar with the firm, Randell gained control of the corporation in 1974 through acquisition of approximately 75 per cent of its stock. Randell disputes these accounts, contending that he only played a minor role in the company.

Once a financial whiz kid, Randell, now 41, promoted the National Student Marketing Corp. into a stock market favorite in the 1960s. The corporation, founded by Randell in 1966, was geared to tap the nation's then flourishing youth market. Its stock soared from $6 a share in 1968 to more than $140 a share the following year. In an acquisition spree in 1969 and 1970, the company gained 25 subsidiaries.

Later, the stock plunged below its original price, and Randell resigned as the corporation's president. In 1974, Randell was sentenced to an 18-month prison term after pleading guilty to stock fraud charges. A federal indictment had accused him of carrying out a conspiracy to use false corporate financial reports to inflate the value of the corporation's stock and enable it to acquire other companies.

Last December, The Washington Post reported that Randell now is a partner in another highly touted venture, known as the Washington Trade Exchange, which is under investigation by federal prosecutors. During the last three years, court records show, Randell also became enmeshed in controversy over the now bankrupt National Commercial Credit Corp.

In court testimony, written statements and interviews, the corporation's two founders and original owners have alleged that Randell became a central figure in the company after gaining control throgh 1974 stock purchases. Both have accused Randell of failing to pay them in full for the stock he bought, asserting that they are owed more than $300,000. The company, founded in 1964, was a sound enterprise when Randell joined it, they have said. Afterward, it foundered.

Harry Koenigsberg, the firm's board chairman, testified in a personal bankruptcy proceeding that in 1974 Randell and another businessman, Lester S. Cotherman, became the corporation's principal operators. Cotherman is said to be a Florida real estate man, and his present whereabouts apparently are unknown.

Harold W. Brammer, the firm's former president and treasurer, described Randell, in an interview, as the central figure in the corporation from 1974 on. "He was the one who dominated it," Brammer said.

In a letter entered among court records, Brammer accused the company's operators, including Randell, of "milking the company dry."

Randell rejected these allegations. "I was not in management and did not play a big role in the firm at all," he said in a telephone interview.

Randell asserted that none of the corporation's stock was held in his name. He said he worked for the firm only from late 1973 to January, 1975, earning an annual salary of $60,000. His main task, he said, was to arrange three bank loans for the business. He said he tried to stave off the firm's bankruptcy and knows nothing about the SEC investigation.

"I was the biggest loser of all," Randell added, saying that he had lent the firm $140,000 and had not been repaid. His wife, Joan, has filed a claim for $176,600 against the firm for principal and interest due at 14 per cent annually on the loan.

It is unclear whether the bankruptcy proceedings or the SEC investigation will fully establish what role Randell and other officials played in the corporation's management in recent years and in its financial collapse. SEC officials have refused to comment on the investigation.

It is clear, however, that Randell became involved in the corporation during a period when its financial troubles were beginning to emerge. Although Randell claims the firm was "prosperous" while he worked for it, the firm's bankruptcy statement reported losses of $700,000 in 1974 and further losses in 1975. It was ruled bankrupt last year by Judge Martin V.B. Bostetter Jr.

Court and other government records also contain several allegations of fraud and financial abuses within the corporation, some of them leveled against Randell.

Randell gained national prominence by his rise and downfall as head of the National Student Marketing Corp. According to a Justice Department spokesman, Randell served almost nine months of his 18-month term at the Federal Prison Camp at Allenwood, Pa., before being paroled in October, 1975.

The Washington Trade Exchange, in which Randell now has become a partner, is an elaborate barter enterprise that allows businesses in the Washington area to trade their merchandise and services with one another through use of special "credits." Federal prosecutors, The Post has reported, have been investigating whether Exchange operators engaged in fraudulent conduct and whether Exchange officials have advocated or participated in questionable or improper tax practices. Randell has said that the Exchange was run in an "absolutely proper manner" and did not engage in wrongdoing.

Randellapparently began work for the National Commercial Credit Corp. during the time he faced prosecution for his role in the National Student Marketing Corp. For this reason, some NCCC officials say, Randell insisted on not being listed officially as an officer or director of National Commercial Credit Corp.

Natinonal Commercial Credit Corp., formerly known as Potomac Valley Homes, Inc., is described in court records and by those familiar with it as a real estate investment firm that bought and sold singel-family homes. The firm purchased some of these homes at low prices from homeowners faced with foreclosuer or other financial hardship. Most of the firm's dealings initially took place in Washington's Maryland and Virginia suburbs, although the corporation apparently started investing later in Florida homes.

The firm also traded in second mortgages, and it raised additional money for real estate investments through offerings of bonds and corporate notes. The bonds and notes promised high interest rates, ranging from 10 to 14 per cent annually.

Some of those familiar with the corporation ascribe its bankruptcy, in part, to unsound real estate investments, especially in Florida; costly purchases of nonfunctioning computer equipment, and high overhead and salaries.

The SEC has subpoenaed corporation records. The Virginia Corporation Commission, which also has conducted an investigation of the firm, has turned over its files to the SEC. The SEC apparently is interviewing some of the firm's former officers, but the SEC has not disclosed the scope or status of its probe.

The firm's dealings have prompted allegations of illegal conduct by Virginia Corporation Commission investigators. Virginia securities investigators alleged in 1975 that National Commercial Credit Corp. had sold unregistered securities, employed unregistered agents and violated antifraud laws. The issues have not been resolved.

In his personal bankruptcy testimony, Koenigsberg, formerly a McLean businessman and board chairman of National Commercial Credit Corp, said he had sold stock representing a 25 per cent interest in the corporation to Randell in February, 1974. Although he was to receive about $240,000 for the stock, Koenigsberg testified, Randell never paid him.

Brammer, the corporation's former president, said in a telephone interview that he sold stock representing aproximately a 49 per cent interest in the corporation to Randell in November him 100,000 for the stock, but eventually gave him only $30,000.

Randell has termed these accounts inaccurate. He said that Koenigsberg's stock was purchased by two Florida persons, whom he did not name, and that Koenigsberg received "some cash' for the stock.

Randell said that Brammer's stock was purchased by a trust, which he did not recall how much money Brammer was offered or paid for his stock.

Whatever the causes of the National Commercial Credit Corp. collapse, its bankruptcy apparently has cost many middle-income families substantial amounts of their personal savings. They appear unlikely to recover any significant part of their investments, according to lawyers involved in the bankruptcy proceedings. Some may be able to take tax writeoffs.

Probably the most prominent investor in the corporation is Rear Adm. David M. Cooney, now the Navy's chief spokesman. He describes his apparent investment loss as "an expensive lesson." Cooney has filed a claim against the corporation for $15,505.

Other investors include well educated, highly skilled men and women, who said in interviews that they normally do not invest their savings recklessly. A computer programmer saaid her family is owed more than $20,000, including money she invested for a son and a daughter, both college students. A retired government statistician and his wife, former Arlington residents now living in Calfornia, filed a claim for $33,640.

Among those hardest hit by the firm's collapse was the Barkson family of Springfield, Va.The Barksons had invested most of their lifetime savings in National Commercial Credit Corp. Natalie B. Barkson, widow of a civilian Navy engineer, has filed a claim for $67,529, and her son, Edward L. J. Barkson, a civilian Navy oceanographer, entered a separate claim for $76,300. Their retirement plans have been ruined, they said.