Zimmer told MSNBC's Steve Kornacki on Saturday that Lt. Gov. Kim Guadagno had "pulled me aside in a parking lot" after a visit to Hoboken in May 2013 and made clear that the deal was tied to Sandy funding.
Zimmer - who gave Kornacki pages of her diary relating the incident - said Guadagno told her: "I know it's not right, I know these things should not be connected, but they are. And if you tell anyone, I'll deny it."
Zimmer also said Department of Community Affairs Commissioner Richard Constable told her that if she moved the project forward, she would get aid.
The developer involved in the deal, the Rockefeller Group, is represented by Wolff & Samson, MSNBC reported. The firm, which has ties to the Christie administration, was founded in part by David Samson, chairman of the board of commissioners at the Port Authority of New York and New Jersey.
In a statement, Christie spokesman Colin Reed attacked MSNBC as a "partisan network that has been openly hostile to Gov. Christie and almost gleeful in their efforts attacking him."
Reed said Hoboken had been approved for $70 million in Sandy aid and "is targeted to get even more" when President Obama's administration approves the next round of federal funding. Zimmer told Kornacki she had requested $127 million in relief funding and had so far received only $342,000.
A federal review of Sandy-related aid was announced earlier in the week.
"It's very clear partisan politics are at play here as Democratic mayors with a political ax to grind come out of the woodwork and try to get their faces on television," Reed said. He said that Christie and Zimmer have had "a productive relationship" and that Zimmer had praised the Republican governor.
Zimmer - who did not endorse Christie, citing the nonpartisan nature of Hoboken's mayoral race - said on MSNBC on Saturday that "I probably should have come forward" sooner.
"But I literally feel I have to act in the best interests of Hoboken," she said.