"That is just so out of character for what this nation stands for and the way we conduct ourselves," Bloomberg told reporters.
Monday, a Lazio spokesman gave a reporter a copy of the 2008 federal tax return of the Cordoba Initiative, the organization that plans to build the mosque. The papers showed assets of about $18,000, and the aide asked rhetorically how the religious organization could raise millions to buy the downtown location just north of the trade center.
Cuomo has been widely quoted as supporting the idea of the mosque being built.
Mosque officials couldn't be reached for comment Monday.
Retired FDNY firefighter Tim Brown of Manhattan, who survived the Sept. 11 attack, agreed with Lazio and said the mosque's finances should be "scrutinized, because we have a history of mosques being funded by Saudi money."
However, Talat Hamdani of Lake Grove, whose NYPD cadet son Mohammad, 23, died at Ground Zero, said calls to investigate the mosque's finances were "sad."
"It's a game plan to undermine the efforts of Muslim-Americans who live here, and just plain bigotry and religious profiling," Hamdani said.
Bloomberg said that while all religions have some bad people, most are "God-fearing."
"We want to make sure that everybody from around the world feels comfortable coming here, living here and praying the way they want to pray," Bloomberg said.
With Maria Alvarez