Washington (CNN) House Judiciary Chairman Jerry Nadler has requested numerous documents and communications related to the administration's "zero-tolerance" policy that led to the separation last year of migrant families who crossed the southern border illegally.

"There remain many unanswered questions about the development and execution of the Trump Administration's family separation or 'zero-tolerance' policy," the New York Democrat wrote in a letter released Monday, one of his early oversight acts as the head of the committee.

The Judiciary Committee, now led by Nadler, is demanding information -- including the existence of "any family separation pilot program," the health and safety of children in government custody and a reunification strategy for families -- from the Departments of Homeland Security, Health and Human Services, and Justice by February 8.

However, given the partial government shutdown, Nadler said, the committee will work with the departments to find a "workable deadline as the shutdown processes."

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