Charges brought against four men arrested Monday in a widening city corruption probe include lurid claims that a top police official roomed with a prostitute during a Las Vegas trip as businessmen spent over $100,000 to ensure unformed officers were available as their private security force.

Two high-ranking New York Police Department officials and a police sergeant who oversaw gun license applications were among the latest arrests in a case that has cast a cloud over the nation's largest municipal police force.

A businessman who contributed heavily to the election campaign of Mayor Bill de Blasio already has pleaded guilty in the case. Earlier this month, federal prosecutors charged the head of the correction officers' union with taking kickbacks. De Blasio, a Democrat, hasn't been implicated in any wrongdoing.

A criminal complaint accompanying the latest charges described how Brooklyn businessman Jeremy Reichberg exploited his connections within the police department to arrange arrests, speed up gun application processing, make tickets disappear, obtain police escorts for him and his friends, get assistance from uniformed personnel to resolve personal disputes and boost security at religious sites and events.

Susan Necheles, Reichberg's lawyer, said in an email: "Mr. Reichberg did not commit a crime."

Reichberg's "only mistake," Necheles said, was befriending a government cooperator "who is desperately trying to get others in trouble in order to curry favor with prosecutors and save his own skin."

The complaint said Reichberg managed to use connections to local law enforcement agencies to shut down a lane of the Lincoln Tunnel connecting New Jersey and Manhattan and obtain a police escort for a businessman visiting the U.S.

In return, the businessman showered his favored police officials with well over $100,000 in benefits from 2012 to 2015, including free flights and hotel rooms, prostitutes, expensive meals, home improvements and prime seats at sporting events, the complaint said.

In announcing the arrests, U.S. Attorney Preet Bharara said Reichberg exchanged bribes for "'cops on call,' a private police for themselves and their friends."

Among those arrested was Deputy Chief Michael Harrington, who was second in command at policeheadquarters in an office responsible for all uniformed operations.

The complaint said Harrington and an unidentified police chief let a businessman buy dinner once or twice a week for 18 months at expensive Manhattan restaurants, where bills ran $400 to $500.

Andrew Weinstein, Harrington's lawyer, said the charges against his client were politically motivated.

"Chief Harrington is a loyal and devoted family man who has an unblemished record and has spent the last three decades working tirelessly to keep New York City safe," Weinstein said. "One would be hard-pressed to find a straighter arrow in their quiver."

Among favors was $59,000 spent on a private jet in February 2013 that took Reichberg, an unidentified detective and James Grant, commander of an Upper East Side precinct, to Las Vegas, the court papers said. The complaint said Reichberg and another businessman arranged for a prostitute to join the flight and spend the weekend with the group, staying in Grant's luxury hotel room.

According to the FBI complaint, the prostitute told law enforcement agents that Grant and others "took advantage of her services" during the trip.

The court papers also contained allegations that Reichberg and an unidentified real estate businessman who has pleaded guilty and is cooperating with authorities wore elf hats as they drove to Grant's Staten Island home on Christmas 2013 to give Grant a video game system for his children and a $1,000 piece of jewelry for his wife. Authorities said they captured Grant on a recorded telephone call a year later grumbling that his two "elves" did not come for Christmas that year.

The head of Grant's union declined to comment. His lawyer didn't immediately return a message seeking comment.

Reichberg, Harrington and Grant were each charged with conspiracy to commit honest services wire fraud.

The fourth person arrested Monday was David Villanueva, an NYPD sergeant assigned to the department's gun license bureau. He was charged with conspiracy to commit bribery. It was not immediately clear who will represent him when the four appear in Manhattan federal court.