NEW YORK (CBSNewYork) — A federal and city probe reportedly has been launched into a $52 million deal made by Mayor Bill de Blasio’s administration to redevelop the Brooklyn Heights Library.

As WCBS 880’s Stephanie Colombini reported, prosecutors are investigating why the city chose to award the Hudson Co. with a bid to revamp the library and convert it into a luxury condominium tower, according to a New York Post report.

The report said the offer by Hudson was $6 million less than another bidder’s, and also included less affordable housing units that would be in a separate location.

The report also said Hudson’s president also has close ties to Mayor de Blasio. He apparently has donated money to de Blasio’s campaign in the past, some of which has been refunded, the newspaper reported.

A representative of de Blasio’s office said the city is unaware of any investigation, but maintained that the selection process followed protocol, the newspaper reported.

The main investigation into team de Blasio, jointly run by the U.S. attorney’s office for New York’s Southern District and by Manhattan District Attorney Cy Vance Jr., is examining de Blasio’s efforts to help Democrats win the state Senate in 2014 and whether donors to his campaign or the Campaign for One New York nonprofit received city benefits in exchange for donations.

Probers are seeking to investigate charges that team de Blasio sought to evade individual campaign limits of $10,300 by having donors make big donations to local county committees, which in turn earmarked and funneled the money to specific candidates. Such methods are against the law.

Also under scrutiny is a city-approved deed change that led to the conversion of the Rivington House nursing home on the Lower East Side into luxury condominiums.

De Blasio has not been accused of any wrongdoing and has repeatedly said he and his team did not violate any campaign finance laws.