After colluding in a $15 million decade-long bribery scheme on interiors work in Manhattan, two Turner Construction Co. former managers and an ex-exec from client Bloomberg LLP pleaded guilty in Manhattan District Court and now face prison time, according to Manhattan District Attorney Cyrus Vance Jr.

The pleas, announced by the DA’s office Oct. 6, are the latest outcome of its larger investigation into bribery and bid-rigging in the highly profitable New York City interiors construction market, estimated as a $9.4-billion sector in the city.

The latest guilty pleas came from Ronald Olson, former Turner vice president and deputy operations manager, and Vito Nigro, its account executive and project superintendent, as well as from Michael Campana, Bloomberg's former construction manager.  Anthony Guzzone, former Bloomberg head of global construction, pleaded guilty in August; according to the DA’s office.

Turner was overseeing interior construction for Bloomberg offices at two Manhattan locations, where the scheme unfolded

According to the DA's office, the executives used inflated subcontractor bids, fake work orders and change orders, and misappropriated unused subcontractor allowance funds. They falsified a Women's Business Enterprise application, so subs could secure work in exchange for cash and other bribes, the office contends.

The district attorney said Guzzone, Olson and Nigro pleaded guilty to first-degree grand larceny and each face three to nine years in state prison. Campana, pleaded guilty to third-degree money laundering and will serve one year in jail and pay $239,800 in restitution.

The four former executives have also been charged in federal court by the U.S. Attorney’s Office for the Southern District of New York for not paying taxes on the illegally obtained funds, the district attorney said. All but Nigro pleaded guilty to one count of tax evasion. Each charge is accompanied with up to five years in prison.  Campana has already been sentenced to two years in federal prison and three years of supervised release and must pay a $10,000 fine.

The district attorney said 22 subcontractor, vendor and company owners, have also pleaded guilty to their roles in the  conspiracy, paying $8.8 million in restitution to date.

The DA’s office did not provide any details beyond its press statement.

New York State Police officers and investigators raided the New York City offices of Turner and Bloomberg in 2017,  using search warrants to probe documents and email threads of the four executives involved in the scheme.

Neither Turner nor Bloomberg were prosecuted in the case. In a statement, the DA cited their cooperation.

“The former Turner employees betrayed our company, their fellow employees, and our core values of honesty and integrity,” a Turner spokesperson said in an Oct. 7 email. “Turner has actively cooperated with law enforcement throughout the investigation.”

Bloomberg, in an email, said the probe "sends a strong message to those who engage in fraud: They will be caught."

City investigations and prosecutions of alleged criminal conspiracies by individuals and firms in the sector date to the 1990s.