U.S. President Donald Trump's choice to lead the Labor Department has admitted to employing an undocumented immigrant as a house cleaner, according to multiple media reports on a revelation that has derailed previous Cabinet nominees.

Andrew Pudzer, chief executive officer of CKE Restaurants Inc [APOLOT.UL], is one of several Trump nominees who faced strong opposition from Senate Democrats and progressive groups. He has criticized an overtime rule championed by the Obama administration and opposed raising the minimum wage to $15 an hour.

An aide for the Senate Committee on Health, Education, Labor and Pensions said a week ago that the panel would not "officially" schedule a hearing until it receives Pudzer's paperwork from the Office of Government Ethics.

Some political strategists said that could signal trouble for the fast-food executive.

Several media reports quoted a statement from Pudzer late on Monday as saying he took action as soon as he learned that his housekeeper, whom he and his wife had employed for a few years, was not legally permitted to work in the United States.

"We immediately ended her employment and offered her assistance in getting legal status," he said in the statement, which was cited by the Huffington Post, the New York Times and other media. He said he and his wife paid back taxes for employing the maid to the U.S. Internal Revenue Service and to the state of California.

Previous presidential appointees have run into problems over immigration issues.

Linda Chavez, nominated for labor secretary by President George W. Bush in 2001, allowed a Guatemalan woman who was in the United States illegally to live in her home and gave her spending money.

Zoe Baird, President Bill Clinton's nominee for attorney general in 1993, withdrew from consideration after she admitted hiring two illegal immigrants as a driver and a nanny and not paying their Social Security taxes.

Another Bush nominee, former New York City police commissioner Bernard Kerik, withdrew his name from consideration for homeland security secretary in 2004 after he disclosed that questions had been raised about the legal status of a former housekeeper and nanny.