Rep. John W. Jenrette Jr. (D-S.C.), one of the congressmen named in the FBI's "sting" operation, has survived a series of federal invesitgations and financial problems since he was elected in 1974 from the state's tobacco-rich 6th District.

Throughout a string of Justice Department inquiries into his private business enterprises and political conduct Jenrette has maintained his innocence.

The first FBI probe began months after he took office. The Justice Department ordered the FBI to investigate Jenrette's campaign contributions after a political rival charged that the congressman, as a candidate, had received a gift from a contractor hired to construct a new federal office building in Florence, S.C.In 1976, the Justice Department announced that it had uncovered no criminal activity and would not seek an indictment against Jenrette.

In May 1976, Jenrette was sued by a business partner who claimed that the congressman had used profits from a joint restaurant venture for personal reasons. The suit was settled out of court.

Another federal investigation began in 1976 into Jenrette's land dealings as a partner in Heritage Shores, a condominum development n North Myrtle Beach. Among the charges probed were newspaper reports that Jenrette's firm between 1970 and 1974 had sold underwater lots to unsuspecting buyers and used underwater acreage to secure collateral for the failing business venture. Jenrette had secured $340,000 in loans for the development from the Myrtle Beach Air Force Credit Union, credit union officials testified.

Jenrette said he had done nothing illegal and had never intended to deceive land buyers. The lengthy grand jury investigation ended with no indictments.

Last year, however, the foreman of the grand jury, William L. (Billy) Lowe, was indicted for obstruction of justice and contempt of court in connection with the Jenrette investigation. Lowe, a longtime friend of the congressman, was charged with leaking information -- including the names and addresses of grand jury members -- to Jenrette.

Jenrette testified at Lowe's trial that he and the foreman had discussed only whether the congressman should appear before the grand jury.

Lowe, however, was convicted of both counts and sentenced in January to a two-year prison term. The Justice Department said then that its investigation into Jenrette's role in the obstruction of justice case was continuing.

Jenrette's name also made headlines in 1979 in connection with a federal probe into drug smuggling activities in Darlington County.The congressman's longtime friend, John Ethridge, a former chairman of the Darlington County Democratic Party, was the initial focus of the probe. But Ethridge told investigators that Jenrette was an important member of the drug smuggling ring and had agreed to allow use of his land on Edisto Island as a landing point for drug smugglers.

Last September Ethridge took the witness stand in the trial of nine co-defendants and said he had lied in implicating Jenrette. Jenrette said Ethridge's testimony vindicated him and "echoes what I've been saying for the past eight months."

The FBI is now using Ethridge as a chief informant in its investigation of a major nationwide drug smuggling operation.