NEW YORK (CNN/Money) - The office of New York Attorney General Eliot Spitzer has ended a probe into a charity run by radio talk show host Don Imus, according to published reports.

The Wall Street Journal reported Friday that Gerald Rosenberg, the chief of the office's charities bureau, wrote a letter to Imus Thursday saying, "Based on the information you submitted to the Charities Bureau, we have determined that no further inquiries concerning the Ranch are needed at this time."

The New York Times reported that the state AG closed the inquiry without any findings of impropriety.

Imus runs a charity for ill children at his 4,000-acre ranch in New Mexico, taking 100 children a year in groups of 10 to the ranch. The charity was the subject of a critical article in the Wall Street Journal on Thursday which questioned the cost of the charity and the personal use of the ranch by Imus and his family.

The article mentioned that there had been questions about the charity by Spitzer office due to a delay in filing the charity's financial information. On his radio show Thursday, Imus acknowledged he had heard from Spitzer's office, but said it was because the state AG was not aware the charity had been granted an extension to file its annual report.

Imus was also sharply critical of the Journal report on the show Thursday, saying that he and his family were at the ranch only 15 days a year without the children.

He again said Friday that the Journal story overstated the costs of running the ranch at $2.6 million, saying that $800,000 of that amount listed on the ranch's filings was for depreciation, not out of pocket costs. He acknowledged that $1.8 million for visits by 100 kids is still expensive, but said it was justified.

"That's what it is. I'm not making any apologies. Would I do it differently, no I wouldn't," he said. "It's changing these kids lives."

Imus also said that he had retained attorney David Boies to represent him in the matter of the Journal article, although he said he had not yet decided whether or not to sue the paper.

Imus said Thursday that he had endorsed Spitzer's run for governor before the questions arose about the ranch. Friday, he suggested that the Journal article might have been motivated by that support for Spitzer, who is a frequent target of criticism by the paper.

But the outspoken talk show host also added that he didn't have any major problem with the paper and its standards -- except in the case of its coverage of this issue.