U.S. Sen. Claire McCaskill, D-Mo., said she has placed a temporary "hold" on the confirmation of Julie Myers as assistant Homeland Security secretary for Immigration and Customs Enforcement after a man who dressed in prison garb and darkened makeup to make him appear African-American was praised for his costume's originality at a Halloween party hosted by Myers, CNN reported Thursday.

McCaskill said she wants Myers to answer questions about the party, including why pictures of her with the costumed Homeland Security worker were allegedly destroyed after questions arose about the costume.

"As the leader of that organization, she should have immediately recognized the problem and asked that person to leave," McCaskill said. "And what really happened was, she judged the costume as one that should get a prize and be recognized and she had her photograph taken with the person in the costume -- and only later came back and apologized and said it was a problem."

Myers was appointed by U.S. President George Bush as a recess appointment in 2006 after her confirmation was stalled by questions about her experience. She was re-nominated for the job in January.