The firm was known as Bovis Lend Lease at the time of the fraud between 1999 and 2009.

Prosecutors said the company had billed clients for hours never worked on site.

The US Attorney’s Office for the Eastern District of New York said: “Bovis intentionally and fraudulently billed clients, from at least 1999 to 2009, for hours that were not worked by labour foremen.

“Bovis systematically added one to two hours of unworked overtime per day to the timesheets for labour foremen.

“Bovis also systematically completed and submitted timesheets falsely listing unworked hours as worked when labour foremen were absent for sick days, major holidays, and weeks of vacation.

“Bovis fraudulently billed its clients for this unworked time and, on public projects, falsely submitted certified payrolls, defrauding taxpayers.

“Finally, Bovis made extra, undisclosed lump sum and stipend payments to a select group of labour foremen and billed those payments to clients as well.

“The clients were unaware of these practices. Pursuant to the deferred prosecution agreement, Bovis has admitted all of the allegations.”

The fraud operated on some of the city’s biggest building projects including Grand Central Terminal and  and the United States Courthouse in which Bovis was charged.

Lend Lease said it has now revised its billing procedures.

The FBI Assistant Director in Charge stated: “Today’s proceedings mark the culmination of a three-year investigation into a systemic pattern of audacious fraud by one of the world’s largest construction firms.

“The overbilling fraud affected city, state, and federal public building projects.

“If you are a New York City resident, Bovis indirectly swindled you on three different levels. Whether projects are publicly or privately funded, padding contracts and skirting the law are crimes. And we are watching.”

For a full statement on the case by the FBI visit here