(CNN) Igor Dvorskiy, a former Southern California test administrator accused of taking bribes in the college admissions scandal, has pleaded guilty to one count of conspiracy to commit racketeering, according to the US Attorney's Office in Massachusetts.

Igor Dvorskiy, outside federal court in March, was accused of accepting bribes.

Clients paid Singer between $15,000 and $75,000 per test and Dvorskiy was paid approximately $10,000 per test to permit the cheating, prosecutors said. Riddell was paid $10,000 per test, authorities said.

Actress Felicity Huffman's daughter was one of many prospective students who used the test center where Dvorskiy administered tests, authorities said.

When Felicity Huffman entered her guilty plea in May, the actress said she "had no knowledge of Mr. Singer paying Mr. Riddell and Mr. Dvorskiy."

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