BALTIMORE, AUG. 6 -- A federal judge threw out claims today that Attorney General Edwin Meese III's involvement in the scandal-racked Wedtech Corp. justified dismissing charges that two brothers who are members of an influential Baltimore political black family tried to block a congressional investigation of Wedtech.

Former Maryland state senator Clarence M. Mitchell III and his brother, state Sen. Michael B. Mitchell (D-Baltimore), are under indictment and are scheduled for trial Oct. 13.

U.S. District Judge Norman P. Ramsey brushed aside arguments that at least the appearance of a conflict of interest existed because Meese heads the Justice Department that supervises federal prosecutors -- including those in Baltimore who brought charges in the Wedtech case.

Defense lawyers argued that Meese may not have personally intervened in the case, but his presence as the attorney general could have caused prosecutors in Baltimore to deflect attention from Meese or discouraged them from seeking "bigger fish" in the investigation.

To the contrary, Ramsey said at the end of a three-hour hearing, the Mitchell investigation was a "home grown" case developed by federal prosecutors in Baltimore with little or no direction from the Justice Department in Washington.

Meese, who allegedly intervened on behalf of Wedtech as a White House official in 1982 and later hired a Wedtech consultant to handle his own investments, is himself under investigation by independent counsel James C. McKay.

"We're going to be vindicated," Clarence Mitchell shouted to reporters gathered on the federal courthouse steps after today's hearing.

He said there was a "Republican conspiracy" by Meese and others in the Reagan administration to discredit blacks by bringing false criminal charges against them here and elsewhere.

"They are trying to destroy black elected leaders in this country . . . . They are doing the work of the Ku Klux Klan."

Michael Mitchell added that numerous supporters, including national civil rights leaders, have helped form a defense fund for the Mitchells.

Also, he said, they have hired the law firm of former senator Edward W. Brooke (R-Mass.), the only black ever elected to the U.S. Senate, to join in the defense with Washington attorneys Abbe D. Lowell and others.

The Mitchells were indicted April 2 on charges of conspiring in 1984 to block an investigation of Wedtech by the House Small Business Committee, headed by their uncle, former representative Parren J. Mitchell (D-Md.).

The committee was looking into whether Wedtech, a New York minority defense contractor, received preferential treatment because of intervention by White House officials, including Meese, then a key White House assistant.

At the time of the Mitchells' indictment in April, Maryland U.S. Attorney Breckinridge L. Willcox described Parren Mitchell as an "unwitting victim" of his nephews' alleged scheme.

The two brothers are charged with accepting $110,000 from Wedtech officials to block the investigation.

The money, according to the indictment, was paid to Michael Mitchell's law firm in Baltimore.

Michael Mitchell in turn gave $25,000 of the total to Clarence Mitchell, the indictment said, and an additional $33,332 to Wedtech consultant Anthony Loscalzo as a kickback for bringing Wedtech's business to the Mitchells.

Ramsey rejected Lowell's request for a full hearing on the Meese conflict-of-interest issue, noting that the Baltimore prosecutors' contacts with the Justice Department in Washington appeared to have been limited and routine.