A top NYPD cop is under internal investigation for buying a slew of properties formerly owned by or connected to Bonnano crime-family boss Vincent “Vinny Gorgeous’’ Basciano and a mob capo, authorities said Monday.

One of the four sites is a Bronx lot where the Mafia used to hold its induction ceremonies up until a few years, according to a report by WNYC radio.

The probe into NYPD Assistant Chief Edward Delatorre, who is known to invest in Bronx real estate and bought the properties, is expected to look at whether Delatorre used his job or any inside knowledge to gain an edge in the purchases.

Police investigators also will likely be investigating even whether he associated with any known criminals while buying them.

NYPD Commissioner James O’Neill said Monday that he had a conversation with a higher-up in the Police Department’s Internal Affairs Bureau about the transactions.

“I had a discussion with Joe Reznick, our deputy commissioner of Internal Affairs, so we opened up an investigation,” O’Neill said at an unrelated news conference at Lincoln Hospital in The Bronx.

Delatorre purchased the properties after the feds crippled the Bonanno crime family in the late 2000s.

Basciano is currently doing time behind bars for murder.

The former mob capo, Dominick Cicale, turned rat against Basciano in the case.

Delatorre’s lawyer, Hayes Young, told the WNYC reporter that the chief never interacted with the Mafia members.

Young didn’t immediately respond to questions from The Post.