DUBLIN — Ireland ordered a Russian diplomat expelled Tuesday after an investigation found that the country's intelligence service used six stolen Irish identities as cover for spies operating in the United States.

Ireland opened the investigation after the FBI smashed a Russian spy ring in June involving 10 men and women posing as American suburbanites in Massachusetts, New York, New Jersey and Virginia. Many had been living apparently normal U.S. lives since the mid-1990s.

It was the second time in 2010 that foreign intelligence agents were found to be using fake Irish passports. Ireland last year expelled an Israeli diplomat after ruling that eight members of a Mossad hit team had traveled on fake Irish passports during a Dubai assassination of a Hamas official.

Both episodes highlighted the value — and apparent ease — of abusing Irish identification documents when undercover agents want to travel unrecognized.

The Department of Foreign Affairs in Dublin said Ireland's police investigation into the Russians' counterfeit passports had determined that Russian diplomatic officials stole the details off genuine passports taken from Irish people during their applications for tourist visas to Russia.

One spy, Anna Chapman — who since has cashed in on her good looks by posing semi-nude in magazines and fronting a Russian TV show on the occult — used passport details stolen from the managing director of a Dublin charity for orphans called To Russia With Love.

Another spy, who lived in New Jersey under the name Richard Murphy but was later revealed to be Russian national Vladimir Guryev, used passports copied in the name of Eunan Doherty, a firefighter from the northwest Irish county of Donegal. Guryev used the Irish passport when traveling to Europe to meet Russian handlers.

The United States in July exchanged the 10 spies for four people convicted in Russia of spying for the West.

Most of the Russian spies had instructions to work their way into influential business and political circles, but they largely failed in that mission. Their fabricated identities included surnames common in Ireland.

The Department of Foreign Affairs said a senior Irish official had issued a face-to-face reprimand Tuesday to Russia's ambassador to Ireland, Vladimir Rakhmanin.

In a statement it said the ambassador was told "that the activities of Russian intelligence services in connection with the forgery of Irish passports and the effective theft of the identity of six Irish citizens are completely unacceptable and not the behavior the [Irish] government would expect from a country with which we have friendly relations."

Russia's embassy in Dublin and Foreign Ministry in Moscow declined to comment.

Ireland declined to identify the Russian Embassy official being expelled as punishment, or to specify whether the official was directly linked to the theft or counterfeiting efforts.

"It is regrettable that this action has been necessary. However, the primary responsibility of the government is to ensure the security and well being of Irish citizens, which includes protection of the integrity of Irish passports," the statement said.