Sol Adler, the longtime executive director of the 92nd Street Y, has been fired in the aftermath of a criminal investigation, the Y announced Friday evening.

In an e-mail sent out shortly before Shabbat, the board explained that it had decided to dismiss Adler after learning he had been engaged in an “undisclosed long term personal relationship” with a subordinate, Cathy Marto. Marto, who had served as the 92Y’s liaison for board and donor relations, is the mother-in-law of a former employee suspected of having demanded and received illegal payments from 92Y vendors.

While the Y e-mail did not name Marto’s son-in-law, the Daily News, in an article Saturday, identified him as Sal Taddeo, a onetime stockbroker arrested in 1997 for his role in a Mafia-run Wall Street scam.

According to the News, Taddeo, who worked for years as the Y’s director of facilities, left in February, shortly before the Y received an anonymous letter about his alleged criminal dealings.

In the course of the Y’s investigation, Marto was “terminated for incomplete or inaccurate answers to investigators,” according to the board’s e-mail, and two other employees were terminated “for engaging in and failing to report suspected inappropriate behavior.”

While the Y decided to dismiss Adler upon learning of his relationship with Marto, immediately after its decision “Mr. Adler entered the hospital very suddenly” and “we determined not to take action on that day out of concern for him and compassion for his family as we sought to learn the details of his condition.”

According to the e-mail Deputy Executive Director Henry Timms will take over as Interim Executive Director while the board conducts a search for a permanent successor to Adler.

“While we know this news is unsettling, we believe that the 92Y Board has taken the appropriate steps so that the kind of activity discovered should never happen again,” it said. “The Board has engaged an independent accounting firm to assist in implementing best financial practices and we are undertaking a top to bottom governance review to ensure that all of the people in our organization live up to the values we espouse.”

Adler, whose compensation totaled $436,370 in 2011, the most recent year for which tax forms are available, had been with the Y since 1978 and its top executive since 1988. The Y website credited him with doubling the number of its programs, and raising more than $80 million.

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