Lt. Gov. Kim Guadagno said the claim by Hoboken Mayor Dawn Zimmer "is not only false but is illogical and does not withstand scrutiny when all of the facts are examined," CNN reported.
"Any suggestion that Sandy funds were tied to the approval of any project in New Jersey is completely false," Guadagno said during a Martin Luther King Jr. event at Union Beach.
Zimmer, a Democrat, told MSNBC Saturday top aides of Christie, a Republican, threatened to withhold millions in Superstorm Sandy recovery money from her hurricane-battered city if she didn't approve a development project Christie favored.
Zimmer said Sunday night she met "for several hours" with investigators from the office of the U.S. attorney for New Jersey in the afternoon.
Guadagno's remarks were the first by a Christie administration official to address the allegations.
Christie is widely seen as a likely 2016 GOP presidential hopeful.
Zimmer said in a statement Sunday she provided investigators with documents, including a personal journal entry, she said supported her allegations Guadagno told her at a May 13, 2013, event she needed to advance a development project sought by a real estate developer with ties to the governor's office if she wanted to receive the money she requested to help protect Hoboken from future flooding.
Richard Constable, Christie's community affairs commissioner, told her the same thing, that Sandy aid "would start flowing" if she backed the development project, Zimmer alleged.
A Christie spokesman was quoted by the Washington Post as saying Zimmer's claims were "outlandishly false."
Spokesman Colin Reed made a slightly different denial in a statement.
"Mayor Zimmer's categorization about her conversation in Hoboken is categorically false," Reed said.
Reed also lashed out at MSNBC for conducting the interview, calling it "a partisan network that has been openly hostile to Governor Christie and almost gleeful in their efforts attacking him."
Guadagno and Constable had no immediate comment.
Zimmer told MSNBC she requested $127 million in hurricane relief for her city of 50,000 across the Hudson River from Manhattan but received only $142,000 so far to defray the cost of a single backup generator, plus $200,000 in recovery grants.
Zimmer was asked on CNN's "State of the Union" Sunday why she didn't come forward with the allegation sooner.
She said she was afraid her story -- accusing an overwhelmingly popular governor of the same kind of political corruption he once targeted as the state's attorney general -- would be ignored.
"I probably should have come forward sooner, but I really didn't think anyone would believe me," she said.
Zimmer said in her statement she would cooperate with the broadening scope of the federal investigation, which began as a look into whether Christie aides engineered a four-day traffic jam in September as retaliation against the Democratic mayor of Fort Lee who didn't endorse the Republican governor's re-election campaign.
"As they pursue this investigation, I will provide any requested information and testify under oath about the facts of what happened when the lieutenant governor came to Hoboken and told me that Sandy aid would be contingent on moving forward with a private development project," she said.
2014: The Year in Fashion [PHOTOS]
White House intruder had a knife