Nicky Diaz Santillan has claimed that Whitman knew she was an illegal immigrant during the nine years she worked for the former eBay CEO.
The Social Security Administration supposedly sent Whitman a letter questioning Santillan's Social Security number, but Whitman says neither she nor her husband received a letter.
The Social Security letter states it does not imply any incorrect information was intentionally provided. It also says it's not a basis by itself for action against the employees, such as laying off or firing. The letter also says it would be a violation of federal law to use it as a justification for adverse action against an employee. The last line states the letter makes no statement about the employee's immigration status.
Whitman held a news conference with her husband, neurosurgeon Dr. Griffith Harsh, standing next to her Thursday in Santa Monica to refute the charges again. When asked whether Santillan might have taken the letter, Whitman said, "It's very possible."
"Neither my husband nor I received any letter from the Social Security Administration," said Whitman.
"These allegations are completely untrue. They lack any merit whatsoever. This is truly a political smear on me, on my family, and based on lies," Whitman said.
"Frankly, I think Jerry Brown should be ashamed of what his allies have tried to do here. Perhaps Jerry Brown has been in politics too long to know any other way to do politics," said Whitman.
"When she confessed to us that she had falsified her employment documents and hiring records way back in 2000, we were surprised and shocked," said Whitman Thursday.
Whitman indicated she might take a polygraph exam to answer questions about hiring Diaz.
However, Allred held a news conference shortly after Whitman's news conference in which she held up the letter from the Social Security Administration that was sent to Whitman's house.
In a corner of a letter from the administration that Allred displayed was a handwritten note to the maid: "Nicky, Please check this. Thanks." It appeared that someone had started filling out the response to the administration.
Allred said the note on the letter proves that Whitman did receive the letter but did not do anything about it.
"Today we have clearly proven with the release of this letter, that Meg Whitman lied to the press and the public when she said, quote, 'We never received that letter and notification,'" said Allred Thursday.
Griffith Harsh released a statement Thursday: "While I honestly do not recall receiving this letter as it was sent to me seven years ago, I can say it is possible that I would've scratched a follow up note on a letter like this."
In an interview later Thursday on KNX am radio station 1070, Whitman said: "[Harsh] does a lot of processing of household paperwork and it would have been unusual if he'd said anything to me about it, so I don't recall him ever saying anything to me about it."
"They didn't return the 2003 letter because they wanted to continue to employ an undocumented worker since she was easier to exploit than a documented one," said Allred Thursday.
Democratic gubernatorial candidate Jerry Brown issued a statement Wednesday in which he showed support for the allegations, though he did not know whether or not they were true.
Allred has donated money to Brown in the past and has been a lifelong Democrat.
Allred said she hasn't endorsed Brown, made any contribution or even seen Brown "for a substantial period of time."
The scandal comes as the two candidates are preparing for a Saturday Spanish language debate that will include questions of importance to the Hispanic community. One of the state's largest public employee unions immediately released a Spanigh language attack ad accusing Whitman of a double standard on the issue of illegal immigration.
The Associated Press contributed to this report.