WASHINGTON (CNN) -- The employee who wore what some said was a racially insensitive Halloween costume to a party hosted by a top immigration official is being directed by the Homeland Security Department Secretary to take administrative leave.

Julie Myers, head of Immigration and Customs Enforcement, called the man's costume "offensive."

The employee's leave will continue while a Department inquiry is conducted, according to Secretary Michael Chertoff.

The employee wore a striped prison outfit, dreadlocks and darkened skin make-up to the party hosted by Julie Myers, head of Immigration and Customs Enforcement.

Myers was on a three-judge panel that originally praised the prisoner costume for "originality."

After some employees complained, Myers apologized for "a few of the costumes," calling them "inappropriate and offensive." She said she and other senior managers "deeply regret that this happened."

A department photographer took a picture of Myers with the man, but the photograph or photographs, originally posted online, were deleted after it was determined the costume was offensive, ICE spokeswoman Kelly Nantel said.

Asked about the controversy at a press conference Tuesday, Chertoff said Myers was "right to apologize for having this proceeding take place" and said she is reaching out to members of Congress and others to make sure "they understood her unwavering commitment to equality and fairness."

"Here is the bottom line: People do dumb things," Chertoff said. "I get very perturbed when there is anything that is done that suggests that with respect to the enforcement of the law, we are anything other than even-handed. I have zero tolerance for racism or discrimination in the area of law enforcement. We have to be tough but we have to be fair. ... The idea that you are going to come and impersonate someone of another ethnic group, I think, is completely unacceptable."

Between 50 and 75 people attended the party, which was a fund-raiser for the Combined Federal Campaign, a federal government collection of charities.

Nantel said one employee, whom she declined to identify, was wearing a black-and-white striped prison outfit, dreadlocks and a skin "bronzer" intended "to make him look African-American." But, she said, it was not immediately apparent that he was wearing the make-up.

"Most people in the room didn't realize he was wearing make-up at all," she said.

"It was unintentioned. The employee did not mean to offend although there were some employees that were rightfully offended by it," Nantel said.

"There were a couple of people who were offended," Nantel said. "When it was confirmed through a conversation with the employee that he was wearing make-up" the employee was counseled and Myers sent out a note to employees apologizing.

"The photo was deleted because there was a determination that the costume was inappropriate," Nantel said.

In a November 2 email to ICE employees, Myers said, "It is now clear that, however unintended, a few of the costumes were inappropriate and offensive. While we were all thrilled to be a part of the CFC fund-raising effort, I and the senior management at ICE deeply regret that this happened."

She reminded all employees to be compliant with the department's diversity training requirement.

Myers has served as head of ICE since January of 2006 but is still awaiting Senate confirmation.

An ICE congressional liaison said ICE officials briefed congressional staffers about the costume party this week as a courtesy. But at least one congressional staffer said they approached ICE after receiving an anonymous fax about the incident.

Myers called House Homeland Security Committee Chairman Bennie Thompson, a Democrat from Mississippi, about the incident and is expected to meet with him before the end of the week, a Thompson spokeswoman told CNN.

Myers also contacted the National Association of African-Americans in the Department of Homeland Security. In a letter to NAADHS members, the group's vice president, Sjon Shavers, said the group "appreciates (Myers) reaching out to us so quickly in order to keep us apprised of the matter and we commend her on moving so swiftly toward appropriate corrective action."

As head of ICE, Myers heads the law enforcement agency charged with enforcing immigration law in the nation's interior. It is the second largest investigative agency in the federal government, with more than 15,000 employees, including 6,000 investigators.

Chertoff "supports the actions that Assistant Secretary Myers has taken," DHS spokeswoman Laura Keehner said. "We do not tolerate inappropriate behavior at DHS.

"The secretary has asked for an inquiry into the facts surrounding the incident. Once the facts have been determined, we will take all necessary and appropriate actions." E-mail to a friend

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