WASHINGTON, Feb. 3 — The Army Corps of Engineers has awarded a contract worth up to $385 million for building temporary immigration detention centers to Kellogg Brown & Root, the Halliburton subsidiary that has been criticized for overcharging the Pentagon for its work in Iraq.
KBR would build the centers for the Homeland Security Department for an unexpected influx of immigrants, to house people in the event of a natural disaster or for new programs that require additional detention space, company executives said. KBR, which announced the contract last month, had a similar contract with immigration agencies from 2000 to last year.
The contract with the Corps of Engineers runs one year, with four optional one-year extensions. Officials of the corps said that they had solicited bids and that KBR was the lone responder.
A spokeswoman for Immigration and Customs Enforcement, Jamie Zuieback, said KBR would build the centers only in an emergency like the one when thousands of Cubans floated on rafts to the United States. She emphasized that the centers might never be built if such an emergency did not arise.
"It's the type of contract that could be used in some kind of mass migration," Ms. Zuieback said.
A spokesman for the corps, Clayton Church, said that the centers could be at unused military sites or temporary structures and that each one would hold up to 5,000 people.
"When there's a large influx of people into the United States, how are we going to feed, house and protect them?" Mr. Church asked. "That's why these kinds of contracts are there."
Mr. Church said that KBR did not end up creating immigration centers under its previous contract, but that it did build temporary shelters for Hurricane Katrina evacuees.
Federal auditors rebuked the company for unsubstantiated billing in its Iraq reconstruction contracts, and it has been criticized because of accusations that Halliburton, led by Dick Cheney before he became vice president, was aided by connections in obtaining contracts. Halliburton executives denied that they charged excessively for the work in Iraq.
Mr. Church said concerns about the Iraq contracts did not affect the awarding of the new contract.
Representative Henry A. Waxman, Democrat of California, who has monitored the company, called the contract worrisome.
"With Halliburton's ever expanding track record of overcharging, it's hard to believe that the administration has decided to entrust Halliburton with even more taxpayer dollars," Mr. Waxman said. "With each new contract, the need for real oversight grows."
In recent months, the Homeland Security Department has promised to increase bed space in its detention centers to hold thousands of illegal immigrants awaiting deportation. In the first quarter of the 2006 fiscal year, nearly 60 percent of the illegal immigrants apprehended from countries other than Mexico were released on their own recognizance.
Domestic security officials have promised to end the releases by increasing the number of detention beds. Last week, domestic security officials announced that they would expand detaining and swiftly deporting illegal immigrants to include those seized near the Canadian border.
Advocates for immigrants said they feared that the new contract was another indication that the government planned to expand the detention of illegal immigrants, including those seeking asylum.
"It's pretty obvious that the intent of the government is to detain more and more people and to expedite their removal," said Cheryl Little, executive director of the Florida Immigrant Advocacy Center in Miami.
Ms. Zuieback said the KBR contract was not intended for that.
"It's not part of any day-to-day enforcement," she said.
She added that she could not provide additional information about the company's statement that the contract was also meant to support the rapid development of new programs.
Halliburton executives, who announced the contract last week, said they were pleased.
"We are especially gratified to be awarded this contract," an executive vice president, Bruce Stanski, said in a statement, "because it builds on our extremely strong track record in the arena of emergency management support."