As Robert J. Lowry tells it, he provided General Services Administration officials with cash, trips, call girls and free painting work on their homes to obtain GSA contracts to paint federal buildings here.

"You paid off or you didn't get the jobs," the 43-year-old Hyattsville painting contractor said of work obtained from GSA, which maintains federal government offices.

But corruption, by Lowry's account, is time-consuming and expensive. To cover up what is being done, "you got to make out phony checks, use nonexistent people, and write out $200 checks to get $150 back," he told The Washington Post. "They (GSA officials) were costing me $1,500 a month.

So Lowry began telling GSA, the FBI, and anyone elso who would listen that compenies doing work for GSA were being paid for phantom work in return for kickbacks they paid to GSA contracting officials. Nothing happened.

By 1976, Lowry was making his charges in three-page, singli-spaced letters addresed to members of Congress, the General Accounting Office, the Justic Department and The Washington Post, besides GSA and the FBI. Justice Department sources say now that the Lowry allegations have provided the basis for current investigations.

In one such letter, on the letterhead of his company, Wibco Inc., of Hyattsville, Lowry said "I . . . Cannot understand GSA'sdesire to allow this nonsense to continue and make it impossible for hard-working, honest contractors to compete and perform this work at as much as a 50 percent savings to the taxpayer in the actual amount of work performed."

In another letter, he claimed he could document hundreds of thousands of dollars in contract fraud.

The fugure truned out to be low. To date, FBI and GSA investigators have found more than $2 million in repair and alteration contracts for work never done. As many as 60 companies are involved in the investigation.

A federal grand jury here has issued subpoenas for documents in the case, and the FBI has spread its investigation to other cities.

One of the firms whose work is being reviewed is Levcon Construction Co. Washington. As reported previosuly, The Washington Post found that while Levcon had painted about half the offices in GSA's own headquarters building at 18th and F streets NW which has 1.9 million square feet at wall and selling surface, Levcon was paid for painting 2.4 million square feet.

In one instance, Levcon was paid $24,375 for painting 187,000 square feet in six elevator penthouses that cointain only 14,316 square feet of area. It also was paid for repairing 122,000 square feet plaster in corridors that contain only 79,000 square feet of space.

Levon with subconstracted part of the work to the son of the GSA official who signed the contract with Levcon.

What role Lowry played in the government investigations is a matter of dispute. GSA lefters to Lowry in early 1976 say the agency had begun an investigation of his charges. However, GSA trace the current prove to the discovery that a Chicago GSA employe was awarding fraudulent contracets. The employe pleaded guilty last year.

A Justice Department source said GSA was not actively, pursuing its investigation in 1976 and was not then cooperating with the FBI. He said the technical complexity of the matters under investigation made GSA's cooperation almost essential.

"In the old case, GSA was not interested, as they are now," the source said. "We've found many of the things Lowry told us (in 1975) have turned out to be true."

What Lowry was saying was relatively simple: that to curcumvent competitive bidding procedures, contractors submit ridiculously low bids for GSA work, assuring themselves they will win a contract. They then get paid for far more work than they actually perform.

"You bid 40 per cent below your cost and make a 400 percent profit," he said.

Until the early 1970s, Lowry said, he paid off GSA building managers ot get contracts. At that time, GSA building managers had the authority to award such contracts themselves. However, they were reqiuired to choose the lowest among at least three bids.

What Lowry did, he said, was to submit all the bids under different company names. The names were either made up or selected from listings in the classifed telephone directory, he said. In return, he generally paid 10 per cent of the amount of a contended to building manager, or extended other favors, he said.

GSA changed the system in 1971. Contracts for $10,000 or more are now awardled by GSA's regional office, although the building managers still order the work. The contracts - called term contracts - require the winning bidders to perform work that comes up during a year at given prices per unit.

he result, according to Lowry, was to open the procedures to more abuses because the contract amounts were larger.

"The term contracts are being used by these individuals (GSA building managers) ot defraud the government on a scale that is all but impossible to believe," Lowry wrote in February 1976 to Kenneth A. Jacobson, who heads GSA's repair and alteration division for the Washington area.

Lowry said recently Jacobson took some steps to improve the system but some steps to improve the system but did not have the power to stop the fraudulent practices.

On May 11, 1976, Lowry provided John F. Galuardi, GSA's regional administrator for the Washington area, with a list of buildings, buliding managers, and companies allegedly involved in fraudulent contracting.

On July 30, 1976, Lowry again wrote to Galuardi, saying he had not received a reply ot his earlier letter.

"I refuse to believe covering up fraud when it occurs has any other purpose than to condone it," Lowry wrote. "And, if you would check, it is fraud to bill for what you do not perform."

Galuardi and Jacobson said they could not talk with a reporter without approval from GSA's public information director, Richard Q. Vawter.

"Based on guidance from the Justice Dempartment. GSA officials do not plan to comment on the investigations," Vawter said.

In October 1976 Lowry and his lawyer, Thomas W. Holland, met with investigators fromthe House Public Works Committee. Lowry said he showed the investigators contracts to paint space that did not exist, but Holland said the investigators never pursued the matter."

"As a taxpaying citizen, it made me shudder," Holland said. "At one point, one of the investigators had to go to Alaska. What is so important in Alaska?"

John N. Stratton, one of the investigators, said recently, "I turned the material over to the General Accounting Office, and they said there was probably something there, but their caseload is too high to handle it."