WASHINGTON — Critics who sued to block the Trump administration from adding a citizenship question to the 2020 census asked a federal judge on Tuesday to punish administration officials, saying the officials had deliberately delayed the lawsuit in order to hide damning evidence — conduct they called “nothing less than a fraud on the court.”

In a motion filed in United States District Court in Manhattan, the plaintiffs charged that the conduct raised “serious questions” about the role that senior Justice Department officials played in assisting that strategy.

The plaintiffs, including the American Civil Liberties Union and a coalition of state and local governments, carried the battle against the citizenship question to the Supreme Court, which ruled in their favor on June 27. Their filing on Tuesday said the administration’s stated rationale for the question — that data from it would help enforce the 1965 Voting Rights Act — was a cover story backed by an incomplete and inaccurate document trail that the Commerce Department “took great pains to curate.”

The filing suggests that senior Commerce Department officials failed to give the plaintiffs documents that would have pointed to what they said was the real reason for adding the question: to give the Republican Party a partisan advantage when population figures from the 2020 census are used to draw new political boundaries in 2021.