Thomas Curran, a lawyer for Turner, said there was “a systemic effort to escape detection by avoiding Turner’s compliance program.”

But industry executives briefed on the investigation, who spoke on condition of anonymity because they don’t want to run afoul of the district attorney’s office, said the raids are part of a broader investigation into other contractors and potential victims that could involve fraud totaling $100 million.

At least eight people have been fired from the companies involved, the companies said, but it appears that no one has been arrested so far. Investigators are continuing to scour the financial records of various executives and interview subcontractors concerning work for Turner, Bloomberg and others.

Nearly four years ago in a similar case, Bloomberg’s former general contractor, Structure Tone, pleaded guilty to corruption charges brought by the Manhattan district attorney’s office and agreed to forfeit $55 million for defrauding Bloomberg, prominent financial institutions, law firms and ad agencies.

Structure Tone admitted that it had electrical, plumbing, drywall and other contractors falsely inflate their bills, adding millions of dollars to the cost of the work. For Structure Tone, the guilty plea was a reprise of a prior investigation, in 1998, when the company pleaded guilty to felony charges for its role in a $2 billion bid-rigging and bribery scheme.

As a result, Bloomberg replaced Structure Tone with Turner.

But investigations and convictions appear to remain a perennial feature of the industry: In 2015, the Manhattan district attorney’s office successfully prosecuted John Cassisi, the former director of global construction for Citibank’s Citi Realty Services, for operating a pay-to-play scheme in which he received $500,000 in cash and gifts from contractors seeking work. Four other titans of the interior construction industry — Plaza Construction, Tishman Construction, Granite Construction and Hunter Roberts Construction Group — paid a combined $92 million in restitution and penalties in recent years for overbilling clients in connection with fraud charges brought by the U.S. Attorney’s Office in Brooklyn.

The district attorney’s office declined to comment on the Bloomberg-Turner case and people familiar with the investigation were reluctant to discuss it for fear of being drawn into the scandal, or because they have been advised not to discuss it. But a picture of the case emerged through interviews with executives at Turner and Bloomberg, people briefed by the district attorney’s office, and lawyers representing people who have been fired.