Naples, Aug 27 (IANS): A team of investigators claim to have unmasked a deep-cover spy from Russia's military intelligence agency, the GRU, who spent a decade posing as a Latin American jewellery designer and partied with NATO staff based in Naples.

The investigators say the woman went by the name of Maria Adela Kuhfeldt Rivera, and told people she met that she was the child of a German father and Peruvian mother, born in the city of Callao, Peru, The Guardian reported.

In fact, she was a career GRU officer from Russia, according to research by Bellingcat in partnership with a number of media outlets including La Repubblica in Italy and Der Spiegel in Germany, and shared with the Guardian before publication.

"Rivera" was what the intelligence community call an illegal, a deep-cover agent trained to pose as a foreigner. Moscow's intelligence agencies have used illegals since the early Soviet period. Sometimes, they stay living in their fake identities for decades.

Posing as "Rivera", the illegal moved between Rome, Malta and Paris, eventually settling in Naples, home of NATO's Allied Joint Force Command, around 2013. She set up a jewellery boutique called Serein and led an active social life, The Guardian reported.

Her acquaintances said that by taking on the role of secretary at the Naples branch of the international Lions Club, she was able to befriend many NATO staff and other affiliates. One NATO employee told the investigators that he had a brief romantic relationship with "Rivera".

It seems "Rivera" was withdrawn by her bosses, who feared that other operatives with similar passport numbers could be compromised. She does not appear to have left Russia again.