Observers say Russia's foreign intelligence, once the pride of the Soviet Union with multi-lingual agents who could live undetected abroad, has suffered a serious blow to its image with the US spy scandal.

Seasoned ex-KGB spooks have queued up to denounce the apparent amateurism of the 10 Kremlin spies arrested and then deported by the United States, who naively used social networking sites and could not conceal accents.

"I'm appalled by what has been happening. It's a farce," scoffed Mikhail Lyubimov, a former Soviet spy who was a long-time KGB resident in Britain.

"If this is espionage then I do not understand their methods.

"I see no sleeper here. In fact I see nothing in this whole story resembling espionage."

The glamorous Anna Chapman, who along with nine others pleaded guilty to being Kremlin agents, stupefied Russian espionage veterans by remaining active on Facebook and a Russian social networking site.

The agents' methods included tactics as basic as the use of invisible ink, Morse code, or the exchange of matching orange bags to transfer false passports.

In their final hearings some of the 10 spoke English with thick Russian accents, hardly the hallmark of a sleeper agent.

"The self promotion that they created on the Internet looks unprofessional to me," Gevork Vartanyan, 86, one of the Soviet Union's most celebrated foreign spies, said.

"The fact that people from the espionage profession allowed such things to happen is very strange," he told the Trud newspaper in a rare interview.

Mr Vartanyan - who says he speaks a mere eight languages "to a good standard" - is the archetype of the successful Soviet spy.

He worked in Tehran in World War II and up to 1951 and was famously credited with foiling a plot to assassinate the allied powers' leaders at the 1943 Tehran conference.

Until 1992 he was deployed as an agent in Europe, Asia and the United States - in operations that remain classified to this day.

As was often the case, he worked in tandem with his wife Goar who he married in 1946 and with whom he still lives in Moscow to this day.

Conspiracy theories

There has even been speculation the spy ring was an elaborate conspiracy aimed at discrediting the reputation of the Russian secret services.

But independent defence analyst Pavel Felgenhauer says they were genuine agents.

"These spies were laughable but they were real. They worked badly and heads are going to roll in the Russian Foreign Intelligence Service (SVR)," he said.

The episode is a highly unwelcome 90th birthday gift for the SVR.

"Our spies have forgotten how to work," Gennady Gudkov, deputy head of the Russian parliament's security committee, said.

"Now we know that not only do our legal system and security forces work badly.

"The last bulwark of the image of our legendary secret services has also collapsed."

- AFP