Former Rep. Frank Clark, a Pennsylvania Democrat beaten for re-election in 1974, has become the target of investigations by a federal grand jury in Pittsburgh, the U.S. attorney's office in Washington and the Internal Revenue Service.

Documents supplied to the grand jury, interviews with many of Clark's former aides and associates, and information on the public record indicate that the investigations involve a series of allegations:

That Clark paid his campaign workers with congressional payroll funds in at least three re-election campaigns.

That Clark arranged for a job for his sister on the staff of a committee on which he served.

That Clark provided a "scholarship" for a constituent by putting her on his office payroll - with no duties to perform - for one month at an annual salary rate of more than $31,000.

That Clark received, in a roundabout way, a $2,500 "fee" from a union directly affected by legislation before his subcommittee.

Clark was asked to comment on these allegations but refused.

Even before most of these allegations came to light, Clark's sense of propriety had evoked comment.

He was the congressman accused by columnist Jack Anderson of charging constituents $2 each fo handling their passport applications. And Clark was the candidate who, after losing a race for re-election, used a loophole in the franking laws to continue sending a "from your congressman" newsletter months after he left the House.

With two groups, however - the maritime industry and 25th District of Pennsylvania constituents - Clark was best known as an agreeable sort who was remarkably generous. Clark's current problems appear to stem from his generosity with federal money.

tr fro add two

One case in which Clark appears to have been particularly generous with government funds involved Gerald Potter, a constituent who described himself as a onetime friend and confidant of the congressman's.

In December, 1973, Potter asked Clark's help in getting some "scholarship" assistance for Lois Greene, the daughter of one of Potter's friends.

In a letter to Clark's administrative side, Arlene Farlow, dated Dec. 27, 1973, Potter wrote: "Frank ask [WORD ILLEGIBLE] me to drop you a line concerning Lois Greene. We talked about putting her on the payroll for a couple of months to help her in her education."

According t congressional payroll records and documents in the hands of the Pittsburgh grand jury, Clark obliged his friend.

Clark's payroll records show that Greene was apid $2,608 in government funds for one month's work in February, 1974. That is equivalent to a rate of $31,296 a year, more than all but Clark's highest paid employee earned that year.

None of the Clark congressional and campaign aides interviewed - including seven Washington staffers and the directors of his three district offices at the time - was aware of any work Greene did for Clark. In fact, none had ever heard of her.

In a telephone interview, Potter said he did not know what kind of work Greene did for Clark or where she worked: "What I was trying to do was to get the kid some kind of scholarship, get her some way that she could further her education."

If Clark was generous with government funds for the benefit of his constituents, he was allegedly even more generous with federal money for campaign purposes.

The FBI is investigating as many as 12 instances in which Clark may have used his House payroll to employ workers in his 1970, 1972 and 1974 campaigns.

In interviews, five persons who appear in Clark's House payroll records as "clerks" said they never did any work connected with Clar's congressional responsibilities. All said they worked only on his campaigns.

The five, paid a total of $10,759 in House payroll funds, are:

Zella Luketic of Bessemer, paid $5,226 between 1970 and 1974, Andrew Lasky of New Castle paid $1,450 in 1972; the Rev. Manford Carter of New Castle, paid $1,200 in 1972; Patricia Kienzle of Butler, paid $758 in 1972, and Mary Jo Iovanella of New Castle, paid $915 in 1974.

In interviews, Clark aides said a sixth person listed on the congressional payroll. Mary Ann Defiore, worked only on Clark's campaigns.DeFiore, who could not be located, was paid $1,200 for two months' work in 1972.

Lasky said DeFiore worked with him on the '72 campaign and never did any work related to Clark's congressional duties.

Most of those interviewed said they had no clear recollection of how they were paid by Clark, although Iovanella said she remembered receiving a check from the House of representatives. Lasky said he recalled being paid by a check that stipulated the money was for campaign work. None of those interviewed said they recalled thinking there was anything unusual about how they were paid at the time.

While Luketic recalled that at one time she worked from one of Clark's congressional offices, she said she worked only on campaign matters. Luketic said most of the work she did was in Bessemer, where Clark never had a congressional office.

When Clark was first elected in 1954, he told a reporter, "I'll probably be the poorest man in Congress when I get there." But Clark quickly accustomed himself to a more expensive lifestyle. He cultivated a taste for expensive cars, including a Lincoln Continental and a customized Cadillac sporting a Rolls Royce grill, a Mark IV tail and a Mercedes-Benz sunroof.

Clark also liked to dine two or three nights a week at Paul Young's and frequently lunched with friends at Club II and the Monocle.

When Clark left Congress at the end of 1974, he was next in line to chair the Merchant Marine and Fisheries Committee and was chairman of a key subcommittee.

It was a subcommittee he inherited from Rep. Edward Garmatz (D-Md.), who retired in 1973 and was recently indicted for allegedly authoring legislation in return for a $15,000 payment for two East Coast shipping firms.

When Garmatz retired, his chief aide, Robert McElroy, found himself out of a job. Clark came to the rescue.

McElroy, who died in 1974, appears on Clark's congressional payroll as having received $20,800 for work in 1973 and 1974.

But six former Clark congressional aides interviewed here said they had no knowledge of any work McElroy did for Clark's congressional office. All said they recalled McElroy making frequent visits to Clark's office and two said they recalled that McElroy handled fund raising for Clark's 1974 campaign.

One former Clark staffer, Bonnie Alderfer, said she thought McElroy was a lobbyist because of his frequent visits to Clark's office.

Ernest Corrado, the chief counsel to the Merchant Marine and Fisheries Committee, who described himself as a close personal friend of McElroy's, said he thought McElroy had worked for Clark's congressional office. He said he had no knowledge of McElroy's doing any work for Clark's Subcommittee, although he surmised that McElroy could have been a "liaison" between Clark's congressional office and the subcommittee.

For his part, Clark suggested to Garmatz in 1971 that the then-chairman of the committee place Clark's sister, Ruth Hoffman, on the committee payroll at $10,000 a year. Garmatz obliged, despite statutory strictures against nepotism in congressional employment.

"It didn't bother me," Garmatz said. "She could have been his wife . . . Why go out and look for someone if you have someone qualified right there."

Chumminess of this sort has carried over many times to the relationships between the committee and its business and union constituents.

Maritime interests contributed more than $30,000 to Clark's 1974 campaign - more than a third of his total expenditures. As chairman of a Merchant Marine subcommittee, Clark that year guided to passage a cargo preference bill to require that a percentage of oil imported into the Unites States be carried on U.S. tankers.

But the bill, which would have been worth millions of dollars annually to the shipping industry, was pocket-vetoed by President Ford at the end of 1974.

Clark's ties with the martime interests also included some private business dealings.

Between 1969 and 1972, Clark and a Pittsburgh insurance agent, John Clemens, attempted to sell a prepaid prescription drug insurance plan to the National Maritime Union (NMU) in New York and the International Longshoremen's and Warehousemen's Union (ILWU) in San Francisco.

During that period, according to documents in the hands of the Pittsburgh grand jury, Clark allowed Clemens to charge telegrams and telephone calls relating to their insurance dealings to Clark's congressional office phone. Clark also helped Clemens get a license to sell insurance in Washington through House District of Columbia Committee staff, and helped him get a license to seell insurance in California. The California license was sent to Clemens at Clark's office, according to the grand jury documents. It was not the only piece of mail Clemens received there.

On Oct. 16, 1972, a $7,500 check from the NMU Pension and Welfare Plan arrived at Clark's Rayburn House office. The check was made out to Clemens for "consulting fees." Enclosed with the check was a letter from the Pension funds executive director, Alvin Shapiro, asking Clark to transfer the moeny to Clemens.

"I am anxious to pay him (Clemens) promptly," Shapiro wrote Clark. But Shapiro appears to have had a problem in paying Clemens. "I note on his bill that there is no mailing address," Shapiro wrote Clark. "I know, however," that you will be seeing him shortly, perhaps even tomorrow, and I would be most appreciative if you could get the check into his hands as promptly and conveniently (sic) as possible.

According to sources who spoke to Clemens independently at the time of the transaction, Clark met with Clemens that week, transferred some of the NMU money to him and allegedly kept $2,500 for himself. The transaction is apparently a focus of the IRS investigation.

In an interview, Shapiro said he had no knowledge that Clark was to get a share of the NMU payment to Clemens. He said the check sent to Clemens was "on the up and up," and that it was sent to Clark's office because Clemens became "unreachable" in late 1971 or the spring of 1972.

Clemens could not be located.

Federal investigators also are looking into the possibility that Clark violated federal campaign reporting laws and that hye may have diverted campaign contributions to his personal use without reporting them on his tax returns. The IRS has sent dozens of copies of a letter concerning Clark's tax liability to associates of the congressman, some of whom say they contributed to Clark's campaigns.

The text of the letter, obtained from several persons who received copies, states: "This office is conducting an investigation of the income tax liability of Frank M. Clark for the years 1972-1975." The letter, dated April 14, 1977, is from Apul A. Sullivan, chief of the IRS Intelligence Division in Pittsburgh. It asks that checks, statements, invoices, receipts or other evidence of payments made to Clark between 1972 and 1975 be sent to the IRS.

It is also known, through interviews with five former congressional employees of Clark who have been interviewed by federal investigators, that the IRS is attempting to determine if Clark failed to report to the IRS money withdrawn from his stationery account or received as reimbursement from staffers who used the account.