WASHINGTON — The Department of Homeland Security transferred nearly $10 million from the Federal Emergency Management Agency to Immigration and Customs Enforcement, according to a budget document released by a Democratic senator late Tuesday night, diverting funds from the relief agency at the start of the hurricane season that began in June. The release of the document comes as a major storm barrels toward the East Coast.

The document, which was released by the office of Senator Jeff Merkley, of Oregon, shows that the money would come from FEMA’s operations and support budget and was transferred into accounts at ICE to pay for detention and removal operations. The document also shows that the Department of Homeland Security transferred money from accounts at Customs and Border Protection that pays for border fencing and technology.

The transfer was a part of more than $200 million the Department of Homeland Security moved from the budgets of other agencies to ICE’s detention and removals.

Mr. Merkley, appearing Tuesday night on “The Rachel Maddow Show” on MSNBC, said the Trump administration was taking money from FEMA’S “response and recovery” and “working hard to find funds for additional detention camps.” Mr. Merkley has been a vocal critic of the administration’s immigration policies.