Bill de Blasio had warned Alberto Carvalho of scrutiny

Weeks before turning down the New York City schools chancellorship on live television, Miami schools chief Alberto Carvalho was warned by Mayor Bill de Blasio that details of an alleged extramarital affair would resurface in the New York news media, de Blasio said Friday.

During his weekly WNYC radio appearance, de Blasio cautioned Carvalho “in great detail” about how “all these issues would be rehashed.”

De Blasio advised that, “there would be scrutiny. It was quite explicit that this is the number-one city in the country, the number-one education job in the country, and if you’re gonna come here, this is the big leagues and expect to get ready for it.”

De Blasio was asked by host Brian Lehrer about a decade-old incident in which emails surfaced suggesting the married Carvalho had had an extramarital affair with an education reporter for the local newspaper. He denied the allegations; she resigned from her job.

On Thursday, Carvalho declared abruptly on live television that he was “honor-bound” to stay in Miami after locals begged during a five-hour-long Miami-Dade school board meeting in which speaker after speaker heaped praise.

De Blasio found out in real time that Carvalho, a formerly homeless undocumented immigrant who rose to lead the nation’s fourth largest school system, was reneging on a job offer accepting last week.

On Friday, de Blasio said he was still confused and surprised at what had happened 24 hours earlier.

“I can’t read his mind,” said de Blasio. “The people who were blindsided were 1.1 million school children in this city who deserved better.”

De Blasio said the search for a new chancellor has restarted, and that the current chief, Carmen Fariña, has agreed to stay for another month.

Fariña announced in December that she would retire after five decades in education.

By Matthew Chayes

matthew.chayes@newsday.comchayesmatthew

Matthew Chayes, a Newsday reporter since 2007, covers New York City.