Hervé Falciani, the French-Italian whistleblower who handed over 100,000 HSBC client accounts to French authorities in 2008, says his decision was prompted by an international network of secret agents and tax officers.

You may have thought of Falciani as a solitary whistleblower. But that’s not the case.

In his latest book, “La Cassaforte degli Evasori,” Falciani describes the existence of a network of well-trained agents who worked in different roles to drag down the banking giant.

Here is how Falciani described it:

We were about a hundred people, all working towards the same objective, but only ten of us worked from within the bank. We were aware that, if the news about our actions would leak, we could have faced dangerous consequences both in our work and our lives.

Falciani says that he was contacted as early as 2006 by people from a highly-sophisticated organisation:

It wasn’t me who tried to contact the secret services. It all happened through some people from HSBC branch in Geneva. They were not Swiss secret agents, I don’t know what nationalities they were, but they were part of an organisation highly sophisticated and perfectly camouflaged. In Switzerland, I would learn, nothing is as it looks.

According to Falciani, Edward Snowden, who leaked classified information about the National Security Agency (NSA) spying on American citizens, was also in Geneva on behalf of the US Central Intelligence Agency.

AP Images, Reuters The impossible connection? Edward Snowden (L) and Herve Falciani (R).

“Snowden’s team [in Geneva] was working on communication systems similar to the ones I had to use myself,” Falciani writes.

Angelo Mincuzzi, co-author of Falciani’s book and managing editor of Il Sole 24 Ore, Italy’s top business publication, alludes to a connection between the HSBC leak and the American secret service in the book’s foreword:

The presence of several intelligence services suggests an undeclared war in the background, a war between the United States and Switzerland to abolish bank secrecy. It is possible, therefore, that the HSBC files were an instrument of clandestine negotiation on behalf of the United States.

In 2012, HSBC was fined $US1.9 billion (£1.25 billion) in the US in a deferred prosecution agreement over money laundering with drug cartels in Mexico.

At that time, it was the largest fine ever paid by a bank to the US government.

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