British bank HSBC helped hundreds of Canadians hide Swiss accounts from authorities to avoid paying millions of dollars in taxes, CBC News has learned.

That’s one of the takeaways gleaned from a massive collection of documents collected by Hervé Falciani, a former employee of the bank, who blew the whistle on his former employer and handed over reams of data to tax authorities, CBC reported.

The Canadian broadcaster reported that those documents were subsequently obtained by French newspaper Le Monde and the International Consortium of Investigative Journalists (ICIJ) who shared them with CBC/Radio-Canada along with a collection of 140 journalists around the world. In total, the documents show emails and banking records for 106,000 customers of HSBC’s Swiss banking arm — altogether they have more than $100 billion US stashed away in their secret accounts.

The value of accounts tied to Canada is around $4 billion Canadian, spread across 1,859 people and companies with ties to this country. A CBC analysis of the Canadian clients’ files, show the level of paranoia and secrecy that the account holders — and their banks — went to in order to keep that money out of reach of tax authorities.