Former independent counsel Kenneth W. Starr spent more than $52 million investigating President Clinton, officially making his Whitewater and Monica S. Lewinsky probe the most costly independent counsel investigation ever, according to a General Accounting Office report released yesterday.

The new GAO numbers, which cover the six-month period from March 31 to Sept. 30, 1999, surpass the spending record of $47.4 million set by Lawrence E. Walsh in the 1980s Iran-contra inquiry.

Robert W. Ray, who replaced Starr last October, is expected to conclude his inquiries within the next year. In March, Ray closed a probe into charges that the Clinton administration improperly obtained FBI files on Republican appointees, saying he had found no evidence of wrongdoing by first lady Hillary Rodham Clinton and senior White House staff.

Five independent counsels investigating Clinton administration officials have spent a total of $95.3 million during the past six years.

The costs of the independent counsels continue to accumulate, despite the end of the independent counsel law. There have been 20 independent counsels appointed to investigate high-level officials since the law was enacted in 1978. Congress allowed the law to expire last July.

Ralph I. Lancaster Jr., the last independent counsel appointed under the old law, opened an inquiry in May 1998 into charges of influence peddling against Labor Secretary Alexis M. Herman. The GAO found that Lancaster has spent more than $3 million in that probe.

Three Clinton-era investigations are drawing to a close. Independent counsel Carol Elder Bruce did not seek indictments against Interior Secretary Bruce Babbitt last October in connection with allegations of illegal political interference in a proposed Indian gambling casino in Wisconsin. Her 18-month investigation had cost more than $5.6 million as of Sept. 30, according to the GAO.

David M. Barrett was appointed in May 1995 to investigate former housing secretary Henry Cisneros's sworn statements to the FBI about payments to his ex-mistress. Barrett's office spent $12 million in a probe that ended last September with Cisneros pleading guilty to a misdemeanor charge of lying to the FBI.

Donald C. Smaltz was appointed in September 1994 to investigate corruption charges against former agriculture secretary Mike Espy, who was acquitted in December 1998. Appeals by other targets in the probe are still pending and led Smaltz's office to spend another $1 million in the most recent six-month period. The total for that probe is now more than $22 million.

INDEPENDENT COUNSELS ADD UP

Spending by independent counsels over the past six months has boosted the total cost of inquiries to $95.3 million over the past six years.

* Independent Counsel: David M. Barrett

Target: Henry Cisneros

6 months (ending 9/99): $1,632,114

Total (as of 9/99): $12,012,116

* Independent Counsel: Carol Elder Bruce

Target: Bruce Babbitt

6 months (ending 9/99): $1,754,356

Total (as of 9/99): $5,638,307

* Independent Counsel: Ralph I. Lancaster Jr.

Target: Alexis Herman

6 months (ending 9/99): $1,664,025

Total (as of 9/99): $3,096,375

* Independent Counsel: Donald C. Smaltz

Target: Mike Espy

6 months (ending 9/99): $1,093,401

Total (as of 9/99): $22,173,555

* Independent Counsel: Kenneth Starr/ Robert W. Ray

Target: Whitewater/ President Clinton

6 months (ending 9/99): $5,303,206

Total (as of 9/99): $52,344,649

* TOTAL: $95,265,002