The money transferred to ICE was a small percentage of FEMA's overall budget but not related to its disaster relief funding budget.
But FEMA says the $10 million was not meant to go to disaster relief and represents an extremely small percentage of what is actually being spent on hurricane recovery.
FEMA receives more than $16 billion in funding each year, about twice the funding earmarked for ICE.
Officials said the money was pulled from accounts that fund office supplies and other expenses - not from FEMA's disaster relief fund. DHS spokesman Tyler Q. Houlton called protests a "sorry attempt to push a false agenda".
As a potentially catastrophic hurricane bears down on the East Coast of the U.S., the shifting of $10 million from FEMA's operating budget to fund immigration detention and deportations is drawing condemnation from Democrats.
In the request, immigration officials said they need the extra money to cover rising costs associated with arrests and deportations.
'$10 million comes out of FEMA when we're facing a hurricane season knowing what's happened previous year, ' he added.
Long, who took over previous year shortly before Hurricane Harvey struck, said he didn't want the investigation to detract from preparations for a major storm was heading for the U.S.
Carlos Giusti/AP, FILEDepartment of Hometown Security personnel converse provides to Santa Ana community residents within the aftermath of Hurricane Maria in Guayama, Puerto Rico, Oct. 5, 2017. Additionally, Hurricane Harvey struck Texas in August and Hurricane Irma struck Florida in September, leaving FEMA stretched thin.
It's unclear when the funds were transferred.
"It would not attain out of the catastrophe reduction fund that funds all the pieces unhurried me and within the field so or not it is some distance a non-voice for us at this moment", administrator Brock Lengthy talked about this morning on ABC's "Beneficial Morning The United States", gesturing to staff at computer systems at FEMA headquarters in Washington.
The document, released by the office of Sen.
The budget document Merkley cited, which was later released and publicized by the DHS Watch program at America's Voice, an advocacy group based in Washington, showed a breakdown of how DHS moved money between different programs and agencies. "We'll take a look at it and see if it was an appropriate use of funds, but when you're talking about hurricane impacts and the billions of dollars, what we're trying to do now is focus on making sure that there are resources available for communities to recover and then maybe get to a better place where they can withstand future storms".
Without the transfer of funds, the document notes, 'ICE will not be able to fulfill its adult detention requirements in FY 2018'.
Money was also taken from other agencies, including millions from the Transportation Security Administration and the U.S. Coast Guard, to help ICE, the document shows. The document mentions Fiscal Year 2018 but doesn't include an exact date.
The documents surfaced, however, just as Hurricane Florence is bearing down on the American coast and is expected to make landfall on Thursday night at North Carolina and SC.
"We have plenty of resources both monetary, staff and commodities to respond to the unsafe storm that is Hurricane Florence", administrator Jeff Byard said.
'The safety of the American people is my absolute highest priority.