Shortly after Republican gubernatorial candidate Meg Whitman said today that she and her husband never knew her housekeeper was an undocumented immigrant, the Los Angeles attorney for Nicandra Diaz Santillan presented what she said were the Social Security documents that prove Whitman is lying.

Attorney Gloria Allred, in a news conference from her office that was streamed on TMZ.com, said the April 22, 2003 letter addressed to the Whitman's home in Atherton included a handwritten note - which Diaz said was that of Whitman's husband, Dr. Griffith Harsh - saying "Nicky, please check this. Thanks."

Harsh never asked about the letter again, Allred said. The Whitmans fired Diaz last year after she told them she was an undocumented immigrant.

Earlier, Whitman appeared in an hour-long press conference with Harsh standing at her side and repeatedly denied that either one of them had ever been contacted by the Social Security Administration about a "mismatched Social Security number for Diaz.

"Absolutely not true," Whitman said. "Neither my husband or I received any letter from the Social Security. "As I understand the process, normally they would have sent a letter to the employee and two weeks later to the employers ... we never saw any such letter."

Whitman - who offered to take a lie-detector test - said her ex-employee was in charge of the house mail, and suggested that Diaz could have "intercepted" the letter.

But Allred produced blow-up copies of what she claimed were the cover letter and a form from the Social Security Administration that was sent to the Whitman's home.

"The letter indicated that the Social Security number provided to the employer ... did not match Nicky's name," Allred said.

She noted that the letter informs the couple of the problem with their employee's Social Security number and "tells the employer, Mrs. Whitman and her husband, what they need to do."

"In response to this letter, neither Meg Whitman nor Dr. Harsh asked Nicky" to give them any additional information, Allred said.

Diaz, who was born in Mexico, was Whitman's housekeeper from 2000 to 2009, and Whitman said she was led to believe from the employment agency that the housekeeper was a legal resident with a state driver's license, Social Security card and immigration documents .

But Diaz Wednesday came forward with Allred and said that Whitman knew she had no legal documents, had mistreated her and failed to pay her for all the hours she worked, then fired her in June 2009 after she asked for help to become a legal citizen.

Whitman and her campaign have alleged that Diaz and Allred are fronts for Democratic groups and the campaign of Democratic gubernatorial candidate Jerry Brown.

Allred, a longtime Democratic supporter, denied the allegation and said she had not been in touch with Brown for years.