The United States deported on Thursday ten Russian agents in exchange for the release of four convicted Western spies held in Russia in their biggest spy swap since the Cold War.

Photo taken on July 8, 2010 shows the Manhattan federal court in New York, the United States. Ten Russian spy suspects in New York will be deported to Russia Thursday night after Russia agreed to release the prisoners and their family members. It marks one of the largest spy swaps between the two countries since the end of the Cold War. [Wu Kaixiang/Xinhua]

The alleged spies, who were captured last week in suburban homes across the Northeast, left for Moscow after pleading guilty in a New York federal court Thursday.

"Today's criminal convictions of 10 Russian agents in Manhattan federal court mark the culmination of years of extraordinary work by the FBI, the U.S. Attorney's Office for the Southern District of New York, and the Department of Justice's National Security Division," said Preet Bharara, the U.S. Attorney for the Southern District of New York.

The conviction of the ten Russian spy suspects brought one of the most notorious U.S.-Russian spy cases in history to an end.

They were accused of appearing to be ordinary Americans for more than a decade while actually leading double lives with false passports, secret code words, fake names, invisible ink and encrypted radio.

The agents ranged from Anna Chapman, a red-haired real-estate agent whose glamorous pictures have filled tabloids around the world, to Vicky Pelaez, a columnist for a Spanish-language newspaper, who said she had "brought a letter with invisible ink" to her contact.

An eleventh defendant was detained in Cyprus and later went missing after his release on bail.

Attorney General Eric Holder said the case took years of work, and the agreement reached Thursday "provides a successful resolution for the United States and its interests."

The ten suspects were detained on June 27, just days after U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev shared a meal at a burger restaurant near Washington, D.C.

However, none of the suspects are believed to have infiltrated the government or obtained classified information.

The Russian Foreign Ministry has acknowledged that some of the suspects involved in the spy case were Russian citizens, but denied that the suspects acted against U.S. interests.

In Russia, the Kremlin said President Medvedev signed a decree pardoning four convicted foreign spies, including Igor Sutyagin, an arms analyst who was reportedly released from a Moscow prison and taken to Vienna.

A Russian court found him guilty of delivering secret data to employees of the British company Alternative Futures, who were actually working for U.S. intelligence services.

The U.S. Justice Department said in a letter Thursday that some of the four prisoners are in poor health and had served lengthy prison terms.

Three of the four were accused by Russia of contacting Western intelligence agencies while they were working for the Russian or Soviet government, the letter said.