US President George W. Bush's choice for the post of homeland security secretary, former New York police commissioner Bernard Kerik, has abruptly withdrawn his nomination after he said he learned that the immigration status of a housekeeper and nanny he employed was in question.
Kerik's decision sent the White House scrambling for a new candidate to oversee the nation's sprawling Department of Homeland Security, charged with helping prevent a repeat of the September 11, 2001 attacks.
Bush's current homeland security adviser, Frances Townsend, is one possible candidate. Others include Undersecretary Asa Hutchinson and Massachusetts Governor Mitt Romney.
The surprise announcement came after news organisations raised questions about some of Kerik's business dealings, including his profitable membership on the board of Taser International, the stun-gun maker.
The White House had earlier on Friday expressed confidence Kerik could ensure there would be no conflicts.
Kerik, 49, nominated by Bush little more than a week ago, said in his withdrawal letter to the president that he appreciated the trust Bush had in him.
He said he discovered the problems about his housekeeper and nanny while completing documents required for Senate confirmation.
"I uncovered information that now leads me to question the immigration status of a person who had been in my employ as a housekeeper and nanny. It has also been brought to my attention that for a period of time during such employment required tax payments and related filings had not been made," he said.
Kerik said he feared that the disclosure would create "intense scrutiny" and "only serve as a significant and unnecessary distraction to the vital efforts of the Department of Homeland Security."
"For these reasons, I must ask you to withdraw my nomination. I personally apologize to you for not having focused on this earlier," Kerik wrote.
Kerik's is the latest high-level nomination since the 1990s derailed by tax and immigration issues related to domestic help.
In addition to the questions about Taser, The New York Timessaid that in 2002, Kerik paid a fine for using a police sergeant and two detectives to research his autobiography.
White House spokesman Scott McClellan said the Bush administration "will move as quickly as we can to name someone else to fill the position."
"Commissioner Kerik informed the White House this evening that he is withdrawing his name for personal reasons from consideration for secretary of homeland security. The president respects his decision," McClellan said in a statement.