Actor Lori Loughlin and her fashion designer husband, Mossimo Giannulli, claim in court documents that federal prosecutors are concealing evidence in the sprawling college admissions scandal.

In the claim, filed Friday in U.S. District Court in Boston, attorneys for the couple said the judge's intervention was “urgently needed” in a case that includes charges of mail fraud, bribery and other crimes.

Loughlin and Giannulli have contested allegations that they paid $500,000 in bribes to help secure their daughters' admissions to the University of Southern California, or USC. They are among dozens of defendants whom prosecutors have accused of having falsified records and laundered millions of dollars to gain access to top-tier universities.

The college prep executive who allegedly helped the couple with the scheme, William Rick Singer, has said he committed similar crimes for 750 families.

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The filing claims that prosecutors have refused to turn over exculpatory evidence that appears to show that Loughlin and Giannulli believed their payments to Singer and USC's athletics department would be used for legitimate purposes.

Prosecutors allege that the couple's daughters gained special athletics admission after they were fraudulently portrayed as rowers.

The U.S. attorney's office in Massachusetts declined to comment Sunday.