Former Cambridge residents Donald H. Heathfield and Tracey L. A. Foley were among the 10 Russian spies who were flown to Vienna, Austria Friday to complete a spy swap with Russia.

Russian officials traded the 10 sleeper agents for four alleged Western spies at Vienna’s international airport, marking the biggest exchange since during the Cold War in 1986. The settlement lasted about one hour, bringing a quick end to an investigation that climaxed in a series of arrests and a swift prosecution.

In the Federal District Court in Manhattan on Thursday, the 10 defendants each pled guilty to a single count of conspiracy to act as an unregistered agent of a foreign government.

The charge to commit money laudering, which was placed on most of the 10 prisoners, was not officially settled until the exchange was successfully completed in Vienna.

Priet Bharara, the U.S. prosecuting attorney in Manhattan, requested that all charges against the 10 defendants are dropped, ending the criminal case, The New York Times reported. All 10 agreed never to return to the United States without permission from the attorney general.

In a moment reminiscent of old-fashioned spy stories, seven of the sleeper agents revealed at Thursday’s arraignment that they had assumed false names during their time in the United States. Heathfield and Foley said that their real names were Andrey Bezrukov and Elena Vavilova.

The couple was transferred from Boston earlier this week to join the eight other defendants in New York for the arraignment, which laid bare the results of a multi-year investigation by the FBI and other federal agencies into a program that officials believe was sanctioned by the Russian foreign intelligence service.

Heathfield—who graduated from the master’s in public administration program at the Harvard Kennedy School of Government in 2000—and his wife were arrested at their Trowbridge Street home in Cambridge on June 27. The couple was charged with conspiracy to act as an agent of a foreign government and conspiracy to commit money laundering.

Heathfield and Foley—who were legally married, according to the former’s attorney Peter B. Krupp—had desired a quick resolution to the prosecution if that would best help their two sons, Timothy and Alexander. Krupp said that he cannot confirm whether they are the couple’s biological children.

Heathfield is a Russian citizen who was educated in Canada and in the United States, according to Krupp, who said he did not know why his client chose Harvard as part of his time in America.

On one side of his double life, Heathfield worked as the chief executive officer of Future Map, a consulting firm that helps governments and businesses develop systems for leadership. As a sleeper agent, he allegedly met with a U.S. government official involved with nuclear weapons research and was tasked with assembling data on U.S. foreign policy.

Foley states on her professional website that she was a real estate agent for Redfin and claims to be a native of Montreal who was educated in Switzerland, Canada, and France.

—Staff writer Xi Yu can be reached at xyu@college.harvard.edu.