A U.S. Secret Service employee accused of lying during testimony in the criminal trial of lifestyle trendsetter Martha Stewart (search) lost a bid on Wednesday to have charges against him dismissed by a federal judge.

Federal prosecutors charge that Larry Stewart (search), a U.S. Secret Service (search) laboratory director and government witness, falsely testified during the closely-watched trial about his involvement in testing ink on a worksheet kept by Martha Stewart's stockbroker.

Martha Stewart, who is not related to Larry Stewart, was convicted of conspiracy and sentenced to five months in prison and five months of house arrest.

An attorney for Larry Stewart sought to have the perjury charges thrown out on Wednesday, arguing that her client's testimony was not material to the trial of Martha Stewart and her stockbroker.

U.S. District Judge Denny Chin rejected the argument, ruling that Larry Stewart's potentially false testimony about his involvement in key tests on the worksheet would "affect the jury's assessment" of his credibility.

"The testimony is clearly material," Chin said. "Whether an expert witness is personally involved in conducting tests is obviously something that would be significant to the jury."

Chin also turned down a request by defense lawyers to have the September trial moved from New York to Washington, D.C., closer to Larry Stewart's home in Bethesda, Md because he has been indefinitely suspended by the Secret Service, has no income, and is funding his defense from personal savings.